Weightlifting Mechanics

Olympic Weightlifting Mechanics

Introduction

Weightlifting or sometimes termed Olympic-style weightlifting can be traced back more than 4,000 years ago. Evidence for both strength training and strength contests can be found in the drawings of weight-lifting and strength movements on the tomb of the Egyptian Prince Baghti dating as far back as 2040 BC. Comprehensive writings from Lu’s Annals (Schodl, 1992) dating from 551 BC also suggest that acts of strength and participation in strength training were valued in ancient China. Historical records reveal that tournaments of strength were not included in the ancient Greek Olympics. However, ancient Greek writings, statues, and training/competition apparatus (e.g., halteres, or throwing stones) signify that resistance training and contests of strength were prevalent in ancient Greece at least as early as 557 BC and that exhibitions and strength contests were likely included in other ancient games (Schodl,1992). Such contests of strength/power gained in popularity into the modern era.

Contemporary Olympic weightlifting requires strength, power, speed of movement, and flexibility. The early stages of modern-day weightlifting can be traced back to the mid-1800s, when numerous clubs in Europe were dedicated to weightlifting and also strength training, particularly in Germany and Austria. The first World Weightlifting Championships were held in London in 1891. Men’s Olympic weightlifting was included in the first modern Olympics in 1896 as a part of the gymnastics program. The sport was not included at the Olympic Games in Paris in 1900 but was re-included for the Games in St Louis in 1904, then vanished again in 1908 and 1912. Olympic weightlifting became a stable fixture in the Olympics at the 1920 Antwerp Games. During the early 1980s, women’s weightlifting increased in popularity, particularly in the United States and China, and the first women’s world championships were held in Florida, in 1987. Women were first included as part of the Olympics weightlifting program during the 2000 Games in Australia.

From 1896 until 1925 the Olympic weightlifting competition included both the one and two arm lifts. In 1925 the IOC restricted the competition to only three lifts: the two hands press, snatch, and clean and jerk (Schodl, 1992). These three lifts were contested from 1925 until 1972 when the press was removed from competition, mainly due to the difficulties in judging the press technique. Currently, weightlifting is contested in almost 165 countries and is one of the seven largest participation sports in the Olympic games.

Importantly, each country has its own governing body that is responsible for holding competitions and certifying athletes and officials according to international rules. Furthermore, national governing bodies may be involved in the education of coaches including coaching clinics and seminars. The IWF was established in 1905 and its headquarters are located in Budapest, Hungary. Information regarding the history, results of international competitions, and educational aspects of Olympic weightlifting are provided by accessing the IWF website at www.iwf.net.

Physical Characteristics of Elite Level Olympic Lifters

The somatotype and physical characteristics of elite male Olympic weightlifters’ are comparable to those of wrestlers and elite level throwers in track and field (Stone, Triplett-McBride, and Stone, 2001). Initial measurements made by Stone and colleagues on female weightlifters also suggest that there are somatotype similarities between female weightlifters and female wrestlers and throwers. While there are exceptions, elite-level weightlifters typically have shorter limbs and a relatively long trunk compared with inactive individuals (Ward, Groppel, and Stone, 2001). At the same relative body mass, elite weightlifters usually possess a relatively high lean body mass and low percent fat compared with untrained subjects or athletes in other sports (Stone and Kirksey, 2000).

The percentage of body fat among elite male weightlifters typically ranges from 5-to-6% in the lighter bodyweight divisions to over 20% in the unrestricted bodyweight categories. For female weightlifters, these percentage of body fat values range from 5-to-10% points higher than male weightlifters. Moreover, weightlifters commonly have relatively higher body mass and lean body mass: height ratio (Stone and Kirksey, 2000). Therefore at the same body mass weightlifters tend to be shorter than other athletes. The relatively high body mass: height ratio compared with untrained individuals is beneficial because it may generate additional leverage. For example, an individual with shorter stature would decrease the relative height to which the bar must be moved to complete a lift.

Additionally, there may be a force-generating advantage from having a high body mass: height ratio. For example, if two athletes of different heights and limb lengths have the same muscle mass, the shorter athlete will have the greatest muscle cross-section generating greater muscle force-generating capacity. Low body fat is often associated with a high lean body mass, frequently reported in elite weightlifters. Therefore, elite weightlifters can be described as being mesomorphic and are shorter than other athletes at the same body mass, and have relatively low body fat content.

The Mechanical Principles of Olympic Lifting

Olympic lifting requires trainees to continue to develop and improve their movement mechanics as these are fundamental to the snatch, clean and jerk lifts. These three lifts in simple terms employ the generation of force against the ground to initially accelerate the barbell in an upward trajectory, then use force against the inertia of the barbell to accelerate the athlete downwards so to be in a position to receive the bar. However, despite the segmented explanation the lifts are performed with fluidity when implemented correctly.

For example, the snatch and clean movements are generally considered in terms of three distinct phases [first pull, second pull and third pull]. Furthermore, there are other elements of the lifts to consider including the preparatory position, starting position, receiving position and recovery. However, the three pull method is a simple yet logical form of communicating relevant movement patterns to conditioning coaches and athletes. The first pull is the phase in which the athlete lifts the barbell from the floor to the point at which the final ascending force production is initiate. This is normally when the bar is about mid-to-upper thigh level. The second pull is the final upward movement that requires an explosive effort with the athlete in full extension. The third pull is the lifters transition from the extended position into the receiving position under the barbell. The principles that dictate the results of the lifters movements are summarised in Table 1.

Table 1. Newtons Laws of Motion

In the initial phase of the snatch or clean movement, the lifter generates muscular force with the legs and hips against the lifting platform, lifting and accelerating the bar upwards. When the lifter reaches their body extension peak and can not drive any more against the platform the barbell will have been accelerated as much as possible and now possess upward momentum. The barbell will continue to temporarily travel in an ascending trajectory even with the removal of any further force applied by the lifter. However, if the lifter performs the lift correctly then the application of force to the barbell will not cease at this point. The effort required to pull against the bar will continue with the arms and the cessation of applied force against the platform via the feet. As signified by the law of reciprocal actions the barbell will travel upwards and the lifter beginning to travel downwards. The magnitude in which each object [barbell and lifter] travels is relative to each other and depends on their relative masses. For example, the heavier the barbell relative to the athlete the less it will travel upward and the more the lifter will be required to travel downward. Lastly, during the final phase of the lift, the bar [with its inertia] acts as an anchor in which the lifter pulls to bring them under it.

What separates the various derivatives [i.e. power snatch and power clean] from the snatch or clean is the interplay of applied force, barbell mass, and the mass of the lifter. If an individual applies maximal force to the barbell, the depth at which it must be received will be dictated by the mass of the barbell and the mass of the lifter. For example, a light barbell will accelerate more and travel higher in comparison to a heavier barbell which will accelerate less and not travel as high. It is also important to note that the lifter can control the force applied with a light barbell being received in the full squat position as a result of the lifter reducing the force required to accelerate the barbell upward. The effort of the lifter to pull under the bar when not applying force against the platform continues the barbell's upward trajectory. This is also true with the jerk movement except the lifter pushes against the barbell rather than pulls against it.

These principles can be condensed into a few simple rules for the implementation of these lifts. Throughout the first and second pulls the individual must maintain contact with the platform [i.e. the ground] until maximal body extension is achieved in order to achieve maximal barbell acceleration. This then allows for correct positioning in which to receive the barbell but requires the lifter aggressively pull the barbell. As this is occurring the athlete can transition quickly and be placed under the bar. An elite level lifter will be proficient in these actions and it would be observed as a single fluid action.

Developing the Foundation: The Squat

The squat movement is the cornerstone to successful Olympic lifts and without a strong and dependable squat, neither the pulling technique nor the pulling power will produce positive weightlifting results. However, there is physical variation among individuals which means that there is not a single unified squat prescription for optimal body positioning; that said, evidence suggests that the central principles of squat movements remain reliable. It is important to be aware that the squat more than any other element of the Olympic lift can be affected by the individual's flexibility restrictions. This will require the coach to develop the trainee's flexibility via modification of exercises and activities till these impediments have been addressed. It is critical that coaches evaluate each individual as this will allow progression to occur and also ensure that poor habits are corrected.

Squat Depth

The depth of a squat is often a heavily debated and contested topic due to the numerous misconception that has been circulating through contemporary media. To clarify this full depth is simply an individual performing a squat to their lowest position possible while maintaining correct posture. The knee joint should therefore close whilst maintaining an upright posture and correctly aligned vertebrae. Squat depth is evaluated in relation to the positioning of the hips and this is governed by the position of the knees and the amount of dorsiflexion of the ankles. Additionally, consideration is necessary regarding the length of the legs, the horizontal position of the hips relative to the feet, the width and amount of external rotation of the feet, and the mass of the upper and lower legs. All these factors above need to be considered and are interdependent and a change in one of these will affect changes in others.

Unfortunately, many fitness professionals and coaches instruct trainees not to move the knees over their feet leading to the hips traveling further back behind the feet. If the individual's hips are behind their base the torso is inclined forward in order for the center of mass to remain balanced over the feet. With the hips lowered in this position misaligns the spine and restricts the spine's ability to be correctly arched. This, therefore, forces the lifter to curl forwards in which to remain balanced. Even though this may appear obvious it is important that these positions are corrected to allow effective and safe support of a barbell in the snatch and clean lifts. Another consideration that coaches should make is if there is inadequate flexibility of the ankles which can result in the knees remaining too far back. If the ankles are unable to correctly dorsiflex then the lower leg cannot reach a sufficient angle to position the knees that permits the hip to reach their intended placement. This is why the heel is lifted in weightlifting shoes as this elevation helps to increase the ankle's range of motion. The length of the upper leg [femur] can also affect the depth of the squat. This is since the length of the femur dictates how far away from the knees the hips will ultimately be. Lifters with superior ankle flexibility and long femurs are capable of deeper squats, while individuals with shorter femurs do not descend as deep.

The Squat Foot Position

Trainees must establish a correct base and optimal foot placement as this will dramatically influence the squat outcome. The width of stance and the degree of external rotation affects the movement and position of the back and hips and if this element is not appropriately implemented can lead to a failed squat or even injury. As discussed earlier, there are evident physical variations between lifters. However, coaches should be aware that the feet must be positioned in a way that permits correct biomechanics of the back, hips, and legs while allowing the greatest possible range of motion.

The initial foot placement should be slightly outside hip width at the heel with the toes turned out [Figure 1]. Ideally, the feet should be positioned approximately 20-35 degrees from the center. With the athlete sitting at the bottom of the squat it is easy for the coach to evaluate and reposition according to leg segmentation, trunk length, hip anatomy, and knee and ankle alignment. There are two basic criteria by which to assess foot placement; (1) are the foot and thigh parallel with each other; and (2) are the hips sitting between the heels. This criterion ensures that the knees and ankles are aligned correctly and are structurally secure in the final position. The positioning of the feet and leg segments should be maintained for the duration of the movement to ensure correct biomechanical alignment. The foot position should be similar for all squat variations [ i.e. back squat, front squat, and overhead squat] and all receiving positions except the jerk.

Figure 1. 30 Degree Feet Placement

Hip Positioning

It is important that the torso is positioned upright during the squat movement that the torso is to allow for the distribution of loading. In the clean movement, the bar is supported directly on the shoulders and requires the torso to be as upright as possible. In the snatch the bar is supported overhead with locked elbows, thus creating a strong and stable positioning. If the torso is not erect it will place additional stress on the shoulders and negatively affect the structural integrity. The necessity to maintain an upright torso requires the hips to be positioned as near to under the shoulders as feasible. This is because the lifter must have a stable base to allow the knees to travel forward and the hips to travel over the feet. The rationale of this knee's forward position is to reduce the contribution of the hamstrings as hip extensors to the squat movement. This is observed in the muscular development of the quadriceps and glutes in elite-level lifters. This quadricep dominant movement may for some athletes feel unnatural at first as these individuals have a predisposition to raise the hips prematurely to provide the quadriceps with greater leverage on the knee and to engage the hamstrings more. This premature hip elevation leads to a forward inclination of the torso that limits the quadricep development and makes it difficult to support the barbell.

Figure 2. Olympic Weightlifter Anatoly Pisarenko Performing a Back Squat

Spinal Alignment and Back Positioning

It is essential that when performing a squat that the spine is in a neutral position and curves through lordosis in the lumbar region and kyphosis in the thoracic region. This is to ensure that the loading pressure is distributed correctly and evenly over the various regions of the vertebrae column. The priority for any individual performing the squat is the maintenance of the lumbar spine’s lordotic arch. The joints of the lumbar vertebrae particularly the fifth lumbar vertebrae that are connected to the sacrum are highly susceptible to injury. This is because these joints are further from the application of force with a load on the shoulders or overhead and consequently the natural fulcrum of the torque.

Adding to this unavoidable structural trait are correctable elements of thoracic spine immobility and hip extensor inflexibility and the subsequent hypermobility of the lumbar spine. It is common for the kyphotic curve of the upper spine to be exaggerated through years of postural habits and muscular imbalances, weaknesses, and impaired activation. Additionally, the mobility of the thoracic vertebrae will be reduced over time due to limited positional changes. This leads to the lumbar spine compensating for the inability of the thoracic spine and hips to move effectively. In doing so the lumbar spine must move through a ROM greater than intended producing laxity in the connective tissue.

When individuals maintain an upright posture in the front and overhead squat the potential for hypertensive injuries is elevated due to the potential instances of compressive force. This erect posture allows for compression and also forward torque acting on the spine and the hips. This places added strain on the posterior connective tissue and excessive pressure on the anterior parts of the vertebrae and discs. Moreover, the torso is marginally inclined forward and the hip extensors are placed under tension encouraging flexion of the spine and making hyperextension more difficult within the scope of correct body and bar placement. For example, when a trainee move from the bottom of a squat the hip extensors and adductors pull the pelvis when under tension in the direction of posterior rotation which produces lumbar flexion. Because of this, it is suggested that the lumbar spine's lordotic arch is exaggerated. This increases the degree of curvature and leads to a reduction in the length of the movement arm and improves the ability to resist the applied force. A greater extension can also improve the leverage of the spinal extensors and subsequently their ability to maintain the extension.

It should be noted that the lumbar curve exaggeration should be prominent at the point of greatest forward torso inclination and reduced as the torso nears vertical to reflect the changing torque and compression of the joints. In the overhead and back squats (Figure 3) the torso does not reach a perfect orientation because the bar placement dictates a slight forward inclination to maintain balance over the base. In the front squat, the torso may reach vertical when the athlete is in the standing position due to the bar placement being in front of the hips.

In the applied setting the spinal curvature is difficult to maintain due to many individuals' flexibility limitations. These include inflexible hip extensors and adductors that inhibit the hip from rotating anteriorly to maintain positioning with the spine as the hip is flexed to move into the bottom phase of the squat. The inability of the pelvis to adequately rotate leads to the lumbar spine taking up the slack. This however at best limits the maintenance of the lordotic exaggeration and at worst significant lumbar flexion.

The curvature of the thoracic spine also needs to be manipulated as the natural kyphosis diminishes the structural integrity when resisting forward torque. This forward curvature places the load further forward in relation to the base of the spine, thus, increasing the movement of the joints and causing the spine to flex and the torso to fall forward. This can be countered in a similar means as lumbar flexion is restricted. In the case of the thoracic spine, the curve should be reduced as much as feasible. This flattening of the thoracic spine produces a complete extension through the entire spine.

By producing a combined arch the lever arm of the back is shortened and reduces the mechanical disadvantage of the muscles extending it and the hip. This leverage of these muscles is therefore improved and increases the strength and stability of the system. This ultimately leads to an increase in performance and also protects the spine from flexion injuries. As with the lumbar curve, the thoracic positioning should be adjusted according to the inclination of the torso (more pronounced at the point of greatest forward inclination).

Figure 3. Bar positioning as observed in the front squat [left], high bar squat [centre] and low bar squat [right]. As can be observed the bar remains balanced over the midfoot in all positions with the back angle altered to accommodate the various bar positioning. This is a critical factor in the differences in the three types of squatting.

Loading and Weight Distribution

Throughout the squat movement, it is important that the weight is evenly distributed across the feet with minor additional loading applied to the heels. If trainees have insufficient flexibility of the hips and ankles then this predictably forces the heels to raise and the weight to transfer towards the balls of the feet as they descend in the squat. This imbalance can be problematic when attempting to stabilize a system that includes a barbell weighing more than the individual's body mass. When in the bottom position of the correctly performed squat the weight may be shifted marginally forward over the feet, however, this is altered when the lifter stands.

In some instances, the outside edges of the trainee's feet will rise at the bottom of the squat and are often because of inadequate ankle flexibility. This impaired ankle flexibility leads to the body attempting to move the knees into the necessary position after maximal ankle flexion has occurred. It is important that ankle flexibility is promoted with technical coaching cues given to the athlete to push out against the floor with the feet assisting. In some instances, athletes may also position their feet excessively wide to accommodate flexibility issues. If the feet are positioned excessively wide this leads to the knees tracking inside them.

Figure 4. Head positioning during the squat movement.

The Head Positioning

During the performance of the squat the lifter's head should remain upright and the face directly forward (Figure 4). In some instances, the athlete will tilt the head back and redirect their focus upward to help drive through the ‘sticking point’ of the squat movement. It has been suggested that some degree of neck extension may help the total back extension, any excessive extension should be discouraged to avoid placing unnecessary strain on the neck.

The eyes should be focused directly ahead and on a fixed point. This focal point should not noticeably change in its relative positioning during the squat movement. If the head is lowered can cause the chest to drop during the ascent potentially leading to a failed lift.

The Stretch-Reflex ‘Bounce’

During the recovery of the clean lifters typically bounce out of the bottom of the squat. This action potentiates the concentric contraction of the muscles and increases the speed of recovery, thus, allowing the athlete to transition more quickly through the sticking point of the squat. Accelerating through the sticking point of the squat reduces the levels of fatigue of the legs and leaves them less fatigued for the jerk movement. This bounce action is the summation of three separate but interrelated features; (1) the stretch reflex; (2) the collision of the upper and lower legs; and (3) the whip of the bar.

When the muscles are stretched to a certain degree they respond with an immediate and powerful involuntary contraction. This myotatic reflex is the same phenomenon that occurs in plyometric training (see Plyometric page). When a lifter performs the squat with suitable speed and tension the stretch reflex can increase the total force production of the concentric movement producing greater momentum during the recovery of the squat. The second element of the ‘bounce’ is the collision of the upper and lower legs with each other. After the lifter collides with the lower legs the remainder of the lifter's body rebounds away from the feet. The larger the athlete's legs the more evident this rebound effect will be.

Lastly, the Olympic barbells are manufactured to exhibit significant elasticity due to the bar's capacity to flex without permanently deforming. This bar design allows the lifter to reach the bottom of the squat and with the bar's elastic energy acts as a spring creating an effective rebound. This whip of the bar reduces the downward force of the bar temporarily and helps with the immediate transition out of the bottom of the squat. It is important to note the degree of the whip is related to the load on the bar. The bounce can be very important for individuals with limited strength in their legs.

The bounce typically should be used in front squats to improve technique, timing, and also neurological adaptations of the stretch reflex for the clean. The back squat should generally be performed with more controlled speed through the bottom ROM ensuring appropriate strength development in the lowest position.

Breathing Mechanics During the Squat

Breathing correctly during the squat helps pressurize the torso and improves the structural integrity of the spine during the movement. The more rigid the spine, the more force generated by the legs can transfer to the bar. The movement of the back will absorb the movement of the legs and hips resulting in the need for the legs to work harder than necessary to move the barbell. This is particularly true when bouncing out of the bottom of the squat. This torso rigidity also reduces peripheral movement and improves the stability and balance of the lifter. Athletes typically draw air in prior to the start of the descent to pressurize the torso. This ensures the optimal pressurization and adds only a few extra seconds to reach repetition.

During heavy front squat movements, some lifters may find it difficult to take in sufficient quantities of air. Therefore, it is suggested that an initial breath be taken and then the bar correctly positioned by a quick adjustment via the legs in order to momentarily lessen the loading. It is important to note that the torso is pressurized through the transition at the bottom of the squat during which forces threaten the structural integrity. The breath should be maintained throughout the full movement; however, some air can be released to help prevent dizziness.

The Olympic Snatch

The Olympic snatch is the first of two lifts contested in contemporary Olympic weightlifting events in which the barbell is lifted from the floor to overhead in a single fluid movement. The pulling mechanics of the snatch are also transferable to the clean and also to the drive of the jerk. It has been reported by strength and conditioning coaches that the snatch is more difficult to learn than the clean and jerk for beginners.

As a result of the difficulty learning these movement patterns, it is suggested that the snatch is taught first and only when the lifter has progressed comfortably with their learning then the inclusion of the clean and jerk should be included. The learning of the snatch should typically start with a length of PVC pipe [substituting for the barbell]. This 5-foot length of pipe is enough to the athlete to start to learn how to learn the movement with a varies of training drills.

The Hand Positioning and Grip

It is important that the hands are in a wide placement for the snatch lift as it reduces the distance the barbell must travel in its path from the ground to overhead. To quickly determine a starting hand placement the athlete should stand upright and hold a bar with a hook grip at arm's length. From this initial positioning the width of the hand positioning will be altered until the bar rests in the crest of the hips. This traditional method will account for not only the arm length and shoulder width but also their relation to the proportions of the lifters trunk and legs. The priority is ensuring that the bar is relative to the hips. To quickly assess if the bar is int the crease of the hips the lifter can lift one knee slightly and if the bar is lifted as the thigh raises the bar is too low. The barbell should make contact with the body just above the public bone to avoid collisions during the final extension.

Foot Placement and Positioning

There are [except for the split position in the split jerk] two main foot positions the pulling and receiving. The pulling position is centred on two criteria ;(1) it generated maximal power production during the pull of the snatch and the clean; (2) permits the lifter to set an appropriate starting position. This position can vary between the clean and snatch movements because of the initial positioning. Feet positioning should be directly under the hips as this will allow maximal power production during the final extension. This permits greater force against the platform as it is being directed downward and therefore upward through the lifter. This ensures that the extension power is not being lost due to an incorrect angle and direction of the force.

The feet should be turned out slightly [approximately 5-15 degrees from centre] and is comfortable for the athlete. If the angle is beyond 15 degrees it may lead to impaired maximal drive against the platform and also make maintaining balance more difficult over the base. From this initial position, the lifters can modify slightly the foot placement based upon their anthropometry with athletes with longer legs widen the stance or turn their feet out slightly to bring the hips closer to the bar. Conversely, this modification of positioning of the torso and hips can be made by splaying the knees to the sides without directly affecting foot placement. Modifications of foot placement should only be made to increase power production and not to correct issues with impaired flexibility.

The lifters line of gravity should pass through the front edge of the heel and the centre of the distance between the balls of the foot and the heel (Figure 5 ). In the applied setting a trainee should be able to stand without falling on any part of the feet from the balls of the foot to the back of the heel if they have suitable balance. The optimum balance can be experienced by standing still and placing pressure on the heels relative to the balls of the feet. When the lifter performs the snatch and the clean they will attempt to maintain the line of gravity of the bar-body system through this identified point of balance. However, during the second pull of the snatch and clean movement the ankle extension places pressure on the balls of the feet while the line of gravity is positioned over the front edge of the heel.

Figure 5. Maintaining balance over the foot. The outer box represents the area of possible balance; the two boxes located internally represent the optimum center of balance.

The Starting Position

As discussed earlier with the squat positioning the default foot position for most individuals is that the feet are turned out between 5-15 degrees from the center. However, some athletes may not have the correct alignment of the knees and ankles and may require minor external rotation of the hips. The lifters that turn their feet out to the sides more have a shallower base and attempting to maintain balance is more problematic. Moreover, excessive rotation can impair the mechanics of the knees and hips which may in terms limit the strength during the pull.

The knees should be splayed to the sides beyond the rotation of the feet to minimize the depth between the bar and the hips. This allows for a more upright torso and leads to easier movement past the knees and also opens the hips to allow greater posture and back extension. This may mean that during the starting position and the first pull the thighs and feet are not necessarily aligned to each other. The anthropometrics of lifters also lead to positional modifications. Longer levered lifters typically have a slightly wider and more externally rotated stance to assist in maintaining correct posture. The threshold to this knee positioning is the contact made between the thighs and the arms. Whilst minimal contact isn’t an issue the legs should not be allowed to encroach into the arms path that would force significant elbow extension and unwanted change in positioning.

The barbell may make contact or be within proximity with the shins in the starting position. Care should be taken that this position does not place the shoulders too far behind the barbell. If this occurs it causes a forward deviation resulting in a slowing of the bar due to friction. The back should be positioned in complete extension with the required lumbar to the thoracic spinal arch. This ensures that the system is structurally rigid and transfers the force generated by the legs and the hips to the bar. The shoulder blades should remain in a neutral position and depressed with the lats engaged forcefully to aid in extending the upper black. This enables the bar to be pushed back toward the body permitting the lifter to control the bar positioning as the pull continues. The arms should be vertical when viewed from the side and as a result, places the shoulders slightly forward of the bar due to the mass and shape of the shoulders. The arms should also be fully internally rotated with the elbows turned to position towards the sides. The head should be upright with the eyes being fixated ahead with a focal point in the distance used to minimize any movement. Shifting the focus of the eyes during the snatch lift can be disruptive and disorienting to the athlete.

The Approach

The bar should be situated over the balls of the feet and will serve as the base in which the shoulders, back, hips, and knee positions will originate. There are two methods when entering the starting position(1) the static start or (2) the dynamic start for the snatch and clean movements. With the static start, the lifter sets the starting position before beginning the lift, whereas the dynamic start initiates the lift without setting the starting position. It has been suggested that the dynamic starts permit the separation of the bar from the floor and the initial pull via the stretch reflex or the generation of more muscle tension through stretching. However, the dynamic start makes it difficult for the coach to evaluate the starting position because of the inconsistency in positioning. Lifters that are well versed in performing this start quickly ‘pop’ the hips down into the position and immediately break the bar from the platform in which to evoke the stretch-shortening reflex. Other lifters slowly set the hips down and then move them into position to start the lift creating muscular tension in the muscles before moving the bar. Both positions make separating the bar easier and lead to less muscular fatigue and increase the speed of the pull.

The static start offers the lifter options and can improve the consistency of the lift compared to the dynamic start. The procedure of approaching the bar should be rehearsed and like the dynamic start, there are two basic types of start positions. The first position requires the lifter to stand with the feet in position and the grip set with the torso leaning over the bar. The second positioning requires the athlete to squat behind the bar with the feet and grip set. It is important to note that regardless of the start the lifter should ensure that they are not out of balance.

The First Pull

The first pull brings the bar from the platform to an appropriately mid-thigh level allowing the scoop to be initiated. This serves as a positioning and power production movement and brings the bar and lifter into an advantageous position from which to implement the second pull (Figure 6). The initiation of the pull from the floor should be controlled [but not slow] with no abrupt shift from slack to tension in the athlete's body. The tension development should be progressive until the force disconnects the bar from the floor, leading to a minor change in back angle as separation occurs. This movement is transitory and as the bar travels the first few inches the back angle should be reached. This angle will remain comparable until the bar reaches mid-to-upper thigh level.

The athlete's weight and bar should be centered over the front edge of the heel due to the bar separation and the CoM will be further forward over the feet due to the bar's starting position. This should be corrected with the athlete shifting the weight back over the feet as this movement will create a minor backward sweep of the barbell off the floor [this can be observed in bar path tracking software]. As the bar ascends it should be positioned as close to the athlete's shins and knees as possible without causing friction. Once the bar transitions past the knees there may be slight contact of the thighs. As the knees move backward during the extension the lats will be fully activated and the bar must be dynamically pushed back towards the body to maintain proximity while permitting the shoulders to be positioned in front of the barbell.

As the bar ascends the knees should be splaying to the slides as initiated in the start position until the bar travels passed them. This allows a more upright posture and minimizes the distance between the hips and the bar. After the bar ascends past the knees the athlete should restrict active splaying of the knees and allow for advantageous positioning to occur for the second pull. The arms should be passively extended and serve as a connection from the torso to the barbell. This passive extension of the elbows allows the arms to be stretched out. However, the elbows should not be purposely locked as this encourages forward barbell swinging during the second pull and interferes with the transition between the second and third pulls when the arms are involved in pulling the athlete under the bar. The arms should, however, be maximally internally rotated with the elbows orientating to the sides and the athlete should continue pulling the bar near the body to maintain proximity. The athlete's spine ultimately is responsible for transmitting the force of the legs and hips to the bar via the arms. During the first pull as discussed earlier, the athlete's alignment and spinal structure should be rigid to ensure that the back is positioned correctly for the start of the second pull in an extended position without creating unwarranted fatigue.

Figure 6. Biomechanics of the snatch

The Second Pull

The second pull is the most explosive and final pull involving the hips and the knees and initiates at approximately the mid-to-upper thigh. The purpose of this pull is to vertically accelerate and elevate the barbell without delaying the transition under the bar. This pulling action is the source of the majority of ascending acceleration of the bar and is continuous with the pull under the bar [third pull]. It should be noted that this final explosion upward is fluid with the second and third pulls considered as a single and continuous action [rather than two phases]. The second pull should be noticeably faster than the first pull with an unbroken transition between the pulls.

The athlete's shoulders should be positioned over the bar as the second pull begins and should be comparable to the final phase of the first pull. The bar should be close to the thighs as the final pull is initiated and dynamically pushed back into the body with the lats fully engaged throughout this movement. The barbell should make full contact with the body at hip level as the hips extend in the second pull. Preferably the barbell should make contact with the body directly in the crease of the hip. This permits the hips and knees to extend in the second pull without the bar disturbing the movement via the contact on the thighs. By ensuring the bar is kept close to the body prior to contact and avoids any impact that springs the bar forward away from the body.

As the bar is approximately level to the mid-to-upper thigh the lifter begins the final extension of the hip with the knees beginning to move forwards. This is often referred to as the scoop element of the double knee bend (DKB) and with accurate timing and positioning will be exceedingly fast. The movement undertaken is similar to a vertical jump [minus lifting a heavyweight and backward positioning]. At the second pull endpoint, the lifter should not be extended vertically as the body should be angled slightly backwards to maintain balance over the feet. The legs should be near vertical and the hips hyperextended to permit the shoulders to be behind the hips. This, therefore, allows for the extension of the hips without distributing the weight of the bar and the athlete's body forward. Additionally, the arms during the second pull serve as a connection between the body and the bar to transfer leg and hip power.

The Double Knee Bend [DKB]

The double knee bend [DKB] ensues in the final phase of the lifter's extension in the second pull. As the lifter's knees near extension as the bar reach approximately mid-to-upper thigh level the lifter initiates the final forceful extension of the hips. As the hip extension ensues the knees marginally flex again and rapidly extend along with the hips (Figure 6). This action is a product of the bi-articular nature of the hamstring and also the need for the body to maintain balance. Due to the hamstrings crossing both the hip and the knee joints the contraction of the hamstrings help affect the aggressive extension of the hip producing the knee to flex involuntarily.

As this flexion is happening the hip extends which forces the partially flexed knees forward under the bar to maintain balance with the upper body rapidly shifting backward. As a result, the knee flexion is quickly countered via a voluntary extension of the knees in the athlete's effort to continue pushing against the platform. This response from the knee is necessary when performing the lifts with correct positioning and speed. Maximal flexion of the knees ensues as the lifter's torso reaches almost vertical, allowing the knees to be positioned forward of the bar and the hips beneath the shoulders. This movement of the knees beneath the bar has often been termed the transition or the scoop.

The effect of performing the DKB is an increase in power production and is similar to those of a vertical jump. However, the lifts are not vertical jumps as the lifter is grasping onto a heavy barbell which inhibits them from fully leaving the platform and the alignment of force is marginally backward instead of vertical. The actions of the athlete to accelerate the bar upward rapidly pulls under the bar while discontinuing the pressure against the platform. It is this forcefully and well-timed change of direction that separates a lift from a jump.

The Third Pull

This pull is when the lifter pulls under the bar after having accelerated it upward. Interestingly, many coaches and athletes misinterpret this part as dropping under the bar or catching the bar. The third pull should be viewed as being as active as the second pull and the athlete should aggressively pull under the barbell. This aggressive explosion of the hips and knees in the second pull ensures that the barbell has accelerated maximally upward. At this point, the bar retains momentum from the force applied to it by the athlete. This upward movement continues momentarily even with the exclusion of all external force application. The distance that the barbell travels decreases as the weight of the bar increases this is because of maximal force applied will have generated less acceleration.

After finishing the extension of the hips and knees in the second pull the athlete instantaneously retracts the hips and bends the knees to initiate the squatting action. During this retraction, the arms violently pull against the bar. Attempts to pull with the arms [or shrug or ] while continuing to drive against the ground results in a sustained extension, during which the bar has reduced time to lose ascending motion. The change in direction must be as forceful as the second pull to exploit the bars temporary ascending inertia. The backward angle of the torso attained at the end of the second pull continues in the opening phase of the third pull allowing the athlete to pull under the bar without disrupting its path. This backward lean should be negligible to ensure that the combined CoM is focused over the base reducing inappropriate movement and restrict the prospective of imbalances. The lifter pulls under the bar with their torso moving forward allowing the head and trunk to pass the bar. The torso continues moving forward until it attains its final position in the squat. Additionally, during the third pull, the feet reposition quickly in which to be in the correct position to receive the bar. The athlete should ideally complete the turnover of the barbell at the same time the feet reconnects with the floor [flat rather on the balls of the feet first].

As the athlete's feet have reconnected with the ground, they drive downwards against the bar. This slows the descent of the barbell and allows for the athlete to drive under the bar and extend the elbows into the receiving position. The athlete should sit into the squat with adequate control and resist the downward motion of the bar. The arms transition from pulling to pushing with the hands flipping over into the final position with wrists extended and hands relaxed while retaining control over the bar.

The Receiving Position

When receiving the bar in the snatch the arm position must be correct when in the overhead position. To receive the bar the shoulder blades must be squeezed back together as this will create a ridge at the base of the neck in which to place the bar. This causes the torso to slightly lean forward and positions the bar over the foot to ensure the lifter is appropriately balanced. Once the athlete is in this position they can press the bar vertically with no alteration needed to the positioning of the torso or shoulders. The elbows should also point midway between down and back with the wrists and hands relaxed and the palms facing towards the ceiling.

The load of the bar and the lifter [as a complete unit] should be positioned over the feet to help remain balanced and stable. As any shift forward of body mass would affect postural changes and lead to a countermovement. For example, when a lifter's torso inclines forward the hips will move back to stop the individual from falling forward. Due to this natural reaction, the barbell remains in the optimal position for support which is over the lifter's feet. The torso leans slightly forward at the bottom of the squat compared to the top and also inclines forward through the middle of the movement as the hips are required to travel back. This forward lean of the torso must be minimized with sufficient flexibility and active postural control. The upright posture must be maintained as the arms and shoulders can only support the heavy loading if the structural integrity of the system remains in place.

The arm positioning should be near vertical from their base at the shoulders placing the bar over the top of the shoulder blades. Due to the hands and barbell being situated behind the forearm the arms will be marginally in front of the vertical line passing through the center of the barbell and the top of the shoulder blades. If the lifter does not maintain these positions it may result in diminished stability and increased barbell movement and comprise the overall ability to support the weight lifted. Maintaining the base of support is crucial and ensures the arms are supported and also that the balance of the barbell is over the feet. Additionally, it links the bar to the body and stabilizes the shoulders against excessive movement. This can be achieved by a complete retraction with upward rotation and elevation of the scapulae.

To achieve this position of the scapulae the head must travel forwards through the arms and the torso marginally inclined forward. Attempts to maintain a vertical torso and head position will subsequently prevent the scapulae from reaching the desired retraction due to the need to maintain bar positioning over the feet and in the arms. To correctly determine the bar positioning is to place the barbell on top of the trapezius with a snatch-width grip and the elbows pointing downwards. Additionally, squeeze the inner edges of the shoulder blades powerfully together while pushing the head forward and pressing the barbell vertically without changing the shoulder blades and head positioning. This squeezing action of the inner edges of the scapulae with an upward rotation will help elevate and retract them as much as possible. Importantly, the barbell should finish directly above the base of the neck and in the same plane of movement in which it began.

Figure 7. Receiving the bar in the snatch position

The Olympic Clean

The clean and jerk is a two-phased lift performed after the snatch in competitions. The barbell is raised from the platform to the athlete's shoulders with a clean movement and then driven from the shoulders to overhead with the jerk. Due to the subdivision in this movement [clean then jerk] and stronger body position, athletes typically can lift significantly greater loads in comparison to the snatch. For beginners, the clean is a relatively easy movement to learn in contrast to the snatch, especially when they are familiar with the snatch action. Lifters that have already learned the snatch often progress far quicker in the clean due to the similar movements.

The Starting Position

The initial positioning for the clean is similar to that of the snatch. There are only minor differences between the two lifts i.e. the difference in the width of grip that result in alterations in the height of the hips, shoulders and conceivable the degree of knee splaying. There are also variations in the lifters feet placement between the snatch and the clean positions. Preferably, the barbell should be positioned over the balls of the lifters feet with the back being set in complete extension and the head and eyes focusing straight forward. The arms should also be extended passively and approximately vertical when observed from the side and also the arms should be internally rotated so that the elbows are orientated to the sides. It is permittable for the bar to be in have light contact or in very close proximity with the lifters shins. It is essential that the athlete's weight is well-adjusted across the foot prior to the separation of the barbell from the floor.

The First Pull

As has been discussed in the previous section (see first pull in the snatch) the first pull brings the bar from the starting position on the platform to the point at which the second pull is instigated (approximately mid-to-upper thigh). The explosive action in the clean is marginally different when compared to the snatch as the bar in the clean is slightly lower due to the narrower hand placement. This positioning permits a powerful second pull that contributes to greater acceleration to the barbell.

The first pull should be measured and only purposefully reduced in speed to ensure correct positioning. Importantly, as the weight increases, the first pull should be forceful but will be relatively slow because of the positional mechanics. As the lifter becomes more accustomed and proficient in the application of the first pull so does the speed. Once the barbell leaves the floor the athletes back angle shifts marginally during the first few inches of the bar movement. This back angle should remain almost the same until the commencement of the final forceful movement. The arm positioning should be relaxed and extended whilst been maximally internally rotated. The athlete's weight should also be placed over the feet at their front edge of the heels.

The Second Pull

The second pull starts with the commencement of the concluding explosive knee and hip movement. This phase of the clean is somewhat different from the snatch in two ways. Firstly, the narrower hand positioning results in the barbell being in contact with the thighs rather than the crease of the hips. Secondly, the distance the barbell travels to its final position is considerably shorter. Due to this reduced point of contact, the knee movement of the scoop will have a significant effect on the barbells horizontal placement. It is important that lifters limit contact between the thighs and the bar as this collision will cause the bar to bounce away from the body (Figure 8). By maintaining the proximity of the bar to the body during the second pull to avoid the bar from ricocheting from the body following contact as the hip extends. This maintenance is achieved due to the combination of correct upright posture (rather than excessive leaning over the bar) and the forceful activation of the lats to push them back toward their body as it travels behind the shoulders.

The Third Pull

The third pull of the clean is considerably different from the snatch. During this phase, the lifter maximally accelerates the bar through the knee and hip extension taking advantage of the inertia of the bar to pull down to the necessary depth to rack the bar on the shoulders. The bar generally rises to almost chest level and during this upward momentum, the athlete has enough downward momentum to be within the relative position so that the elbows can aid in the turnover. The lifter aggressively retracts their shoulder blades and pulls the elbow back to start their path around the barbell back into the shoulders rather than merely pulling the body down. The aggressive arm pull with the elimination of pressure against the floor immediately upon the completion of hip and knee extension in the second pull alters the lifters direction and accelerates them under the barbell. This instantaneous and aggressive acceleration permits the turnover of the arms.

The path of the elbows during this turnover is essential for a successful attempt. The bar is the pivot point for the arms as they move into the rack position and disruption of this movement will alter the athlete or barbell from their respective paths. For example, if the elbows travel back prematurely, rather than upwards and to the sides may conceivably lead to the lifter failing to accelerate downwards sufficiently due to the misdirection of the force of the arm flexion. The arms should rotate quickly around the bar to permit entry into the rack position. This movement should be aggressive to ensure that the elbows are high enough to allow time for delivery of the bar. As the elbows are ‘whipped’ into position the grip of the barbell is intuitively released. However, if the grip is overly tight at this point will prevent the release of the grip and impair correct rack positioning. Importantly, a tight grip on the barbell may greatly reduce the speed of the elbows final movement and prevent the elbows maximal elevation (Figure 8). As the pull under the bar is initiated the athlete's feet start their transition from the pulling to receiving position.

Figure 8. Second, third pull into recovery in the clean position

The Receiving Position

Once the athlete completes the third pull they will be placed in a front squat position. This position is dependent on how high the barbell was raised during the second pull and also how quickly the athlete positioned themselves upper the bar. The lifters must make a conscious effort to rack the bar quickly as this creates more time to ensure correct positioning and also prepare for the force at the eccentric phase of the squat (Figure 8).

The most critical component of receiving the bar in a clean is the stability of the torso. The positioning of the bar on the shoulders creates a substantial lever arm on the spine even with an upright torso. The force of the bar in this position encourages the upper back to round forward and as this happens increases the length of the lever on the back and pulls the lifter forward. This structural collapse can rapidly exceed the lifter's ability to compensate and results in a failed recovery. To ensure that structural collapse does not occur it is essential that the barbell remains close to the body during the lift and is correctly placed on the shoulders. Additionally, the torso needs to be pressurized and this should have occurred before the initiation of the lift. The lifter may involuntary release a small quantity of air during the second pull, however, due to the movement speed, there will be no opportunity to take in the air during this phase.

The elbows in this section should be elevated to ensure the correct rack position. Once the barbell is racked on the shoulders the athlete should dynamically resist the downward force of the bar and regulate (where possible) the speed as this supports the bar on the torso. However, when the athlete performs a heavy clean no amount of resistance to the barbell's downward force will be capable of stopping it above the bottom of the squat. All that the lifters can endeavor to do is resist the downward force to stabilize and control the weight without foregoing the opportunity for the bounce out of the bottom of the squat.

The Recovery

The recovery phase of the clean is no different from performing the front squat. The only difference is entering the bottom squat position is generally faster with a quicker transition from a greater bounce effect due to the bar's downward speed. The lifter's weight should be stable over their feet at the front edge of the heel. The torso should be upright with the spine held in complete extension with elevated elbows and the torso pressurized. Dynamically driving the elbows upwards when transitioning to the squat recovery encourages correct spinal positioning and also faster recovery. Additionally, driving the elbows up helps to discourage premature elevation of the hips. Through repetition and practice, this movement should develop a reflex associated with the bottom of the squat.

The athlete should consciously accelerate upward throughout the recovery as the momentum created from the bounce is maximized and helps to minimize the slowing that occurs at the difficult mid-point of the squat. Intermittently an athlete may fail with their timing or positioning and this prevents them from recovering immediately. This should be avoided where possible and athletes with relatively weak legs exiting the recovery without a bounce may prove to be problematic. From the bottom position, the lifter performs quick activation of the glutes and the quadriceps generating momentum and height initiating full recovery.

The Jerk

There are three variants of the jerk movement involving two different receiving positions of the feet. These are the power jerk, squat jerk, and split jerk.

The power jerk (also known as the push jerk) is termed due to the receiving position being similar to the power snatch and power clean. The feet are positioned in the squat stance with the thighs above horizontal. This movement is a common training exercise but is seldom used in competition due to the greater demand placed on bar elevation. Furthermore, there is limited scope for error in bar positioning and the bar must be driven precisely into position overhead to ensure that the lifter maintains its stability.

The squat jerk foot positioning is similar to that of the power jerk but the athlete receives the position in a squat. This requires less elevation of the bar than the power jerk but requires greater flexibility due to the relatively narrow grip in the overhead squat position. Additionally, greater bar placement is required and any deviation of positioning leads to problematic instability. Athletes and coaches should consider the difficulty of recovering from the bottom of a close grip overhead squat specifically following the effort needed to clean the weight. This movement in a competition is uncommon as individuals need to possess the flexibility, accuracy, and leg strength to execute this successfully.

The most common style used in competition is the split jerk this allows the individuals to receive with greater depth and recover relatively easily. It also accommodates greater accuracy in the overhead position of the bar than the other two movements and ultimately provides greater stability in all directions. The split stance permits the same hip depth as the parallel squat and provides stability due to the expansion of the athlete's base. The foot width is again comparable to the squat with an even greater length. Such an extensive base improves the direct stability of the system and allows for corrective adjustment of the bar when overhead.

The Split Positioning

There are two-foot positions for the jerk namely the drive position and the receiving position. The initial starting positioning is with the feet marginally wider than hip-width with the feet turned out between 5-15 degrees. It is important to determine which leg the lifter should lead with. Once this has been selected the lifter needs to learn the split positioning. To do so the lifter enters into a lunge with the predetermined leg leading forward. The width of the feet should be comparable to that of the individual's squat stance ensuring lateral stability. This is due to the center of gravity of the lifter and the bar being higher off the floor and difficult to stabilize.

The lead foot will be flat on the floor with weight being distributed near the heel and the foot forward or the toe turned in marginally. The heel of the back foot will be elevated and the weight driving through the balls of the foot. The rear foot will also be turned inwards with the toe pointing towards the midline and the heel to the outside. This is to ensure that the foot is kept in line with the lower leg as it would be if squatting or standing. Any misalignment can impact the structural integrity and opens the ankle for rolling out under the loading of the jerk. The length of the split should be altered until the shin of the lead leg is near vertical with the front thigh (approx. 20-40 degrees to the floor). The back knee should remain flexed as this reduces the tension of the ankle while permitting the heel to be elevated. Additionally, this also prevents hyperextension of the knee upon receiving the weight and reduces the hip flexor tension on the pelvis preventing anterior rotation and the subsequent hyperextension of the lumbar spine.

This bend in the back knee is essential for ensuring complete lockout of the jerk and balance of the lifter under the weight. Permitting a bend in the back knee along with the front knee when driving under the weight allows the lifter to move straight down and ensures a supportive position while under the bar. If the back knee was locked while the front knee is bending the lifter will push the barbell forward which will make the positioning problematic. The knee bend does not have to be excessive but needs to be recognized in every jerk to ensure better positioning under the bar. The split depth should be viewed as a default position for executing the jerk and should be altered depending on the demands of increasing weight. The hip depth in the split during lifting is determined by the lifter's ability to evaluate the barbell and also how far underneath they must push their selves in order to receive it with full arm extension. The individual's torso should be vertical with a slight incline forward to correct the overhead position. When the bar is added to the system the hips will be placed under the bar and the spine remaining in a neutral curvature.