Mechanical Demands of the Hang Power Clean and Jump Shrug: A Joint-Level Perspective

Abstract

Kipp, K, Malloy, PJ, Smith, J, Giordanelli, MD, Kiely, MT, Geiser, CF, and Suchomel, TJ. Mechanical demands of the hang power clean and jump shrug: a joint-level perspective. J Strength Cond Res 32(2): 466-474, 2018-The purpose of this study was to investigate the joint- and load-dependent changes in the mechanical demands of the lower extremity joints during the hang power clean (HPC) and the jump shrug (JS). Fifteen male lacrosse players were recruited from a National Collegiate Athletic Association DI team, and completed 3 sets of the HPC and JS at 30, 50, and 70% of their HPC 1 repetition maximum (1RM HPC) in a counterbalanced and randomized order. Motion analysis and force plate technology were used to calculate the positive work, propulsive phase duration, and peak concentric power at the hip, knee, and ankle joints. Separate 3-way analysis of variances were used to determine the interaction and main effects of joint, load, and lift type on the 3 dependent variables. The results indicated that the mechanics during the HPC and JS exhibit joint-, load-, and lift-dependent behavior. When averaged across joints, the positive work during both lifts increased progressively with external load, but was greater during the JS at 30 and 50% of 1RM HPC than during the HPC. The JS was also characterized by greater hip and knee work when averaged across loads. The joint-averaged propulsive phase duration was lower at 30% than at 50 and 70% of 1RM HPC for both lifts. Furthermore, the load-averaged propulsive phase duration was greater for the hip than the knee and ankle joint. The joint-averaged peak concentric power was the greatest at 70% of 1RM for the HPC and at 30%-50% of 1RM for the JS. In addition, the joint-averaged peak concentric power of the JS was greater than that of the HPC. Furthermore, the load-averaged peak knee and ankle concentric joint powers were greater during the execution of the JS than the HPC. However, the load-averaged power of all joints differed only during the HPC, but was similar between the hip and knee joints for the JS. Collectively, these results indicate that compared with the HPC the JS is characterized by greater hip and knee positive joint work, and greater knee and ankle peak concentric joint power, especially if performed at 30 and 50% of 1RM HPC. This study provides important novel information about the mechanical demands of 2 commonly used exercises and should be considered in the design of resistance training programs that aim to improve the explosiveness of the lower extremity joints.

Enhancing the Force-Velocity Profile of Athletes Using Weightlifting Derivatives

“…Research investigating the optimal load for weightlifting pulling derivatives is limited because of the lack of criteria that indicates a successful repetition (100). However, several studies have suggested that lighter loads (i.e., 30-45% 1RM hang power clean) may optimize training stimuli for the jump shrug (60,92,(102)(103)(104)(105) and hang high pull (94,102,104) 33-35,73) may produce the optimal training stimulus for velocity and power adaptations during the clean/snatch pull from the floor. Practitioners should however consider that the optimal load for power production may be specific to the joint, athlete plus load system, or the bar (66), may be altered based on the relative strength of the athlete (87), and may be impacted by movement pattern and the fatigue status of the athlete Strength and Conditioning Journal | www.nsca-scj.com (54).…”

“…Although previous research supports the notion that weightlifting catching derivatives may train an athlete's ability to "absorb" a load during impact activities (68), more recent studies indicate that weightlifting pulling derivatives that exclude the catch phase may produce a similar or greater load absorption stimulus (i.e., loading work, mean force, and duration) following the second pull compared with weightlifting catching derivatives (17,99). Moreover, further research has demonstrated that weightlifting pulling derivatives produce comparable (11,12) or greater (60,102,104,105) force, velocity, and power characteristics during the second pull compared with weightlifting movements that include a catch element. Although the complete removal of weightlifting catching derivatives is not being suggested, the integration of weightlifting pulling derivatives into resistance training programs should be considered for the comprehensive development of an athlete's forcevelocity profile, as elimination of the catch phase permits the use of greater loads (i.e., greater forces) (14,16,39) and potentially greater velocities (95,101).…”

“…The placement of the jump shrug and hang high pull on the force-velocity curve is supported by previous research demonstrating that the jump shrug (104,105) and the hang high pull (104) produced higher velocities compared with the hang power clean. Moreover, previous research also indicates that these exercises may be best prescribed using lighter loads to maximize power and velocity (60,92,94,(102)(103)(104)(105). Additional research also supports the placement of the power clean, power clean from the knee, and midthigh power clean based on the 1RM (i.e., greater force or less force) that may be achieved for each exercise (56).…”

Body Mass As The Optimal Load Predictor For Power Clean Variations: A Practical Approach

“…Interestingly, power production was higher in the MTP from 30-70% BM when compared to HPC, but at 80-90% BM this shifted toward HPC prevalence over MTP. As stated before, there are several factors such as rate of force development (6), impulse (6,23), propulsion (34) and joint internal power output (20) that contribute to effective levels of power production. That reinforces the idea of prescribing not only the exercises that work the same musculature/joints but also the ones that are more similar in nature with sport-specific moves, so the athlete can enhance performance more effectively.…”

“…Consequently, the strategy that has largely been used to determine the training load for these exercises is using percentages of the PC or HPC (6,27,33). However, the application of this method requires the individual to become very proficient in a more complex exercise to determine the training load of less complex exercises (5,20,34).…”