Effect of resistance mode on squat and jump kinematics and kinetics
Date of Award
Master of Science
School of Exercise, Biomedical and Health Sciences
Faculty of Computing, Health and Science
This thesis provides an in depth investigation of the following four resistance modes: constant resistance (CR), rubber based resistance (RBR), pneumatic resistance (PnR) and standard link steel chain (SLSC) resistance; where the following issues were assessed: i) a review of literature discussing the kinematics, kinetics, practical applications and limitations of constant, accommodating and vaiiable resistance modes; ii) a descriptive analysis of the resistive properties of RBR, SLSC and PnR; and iii) an experimental study researching the kinematic and kinetic effects of performing squat and jump type movements with CR, PnR, RBR and SLSC.
The review provides valuable biomechanical information with regards to human strength curves ( def. which approximate the torque production capabilities of single and multi-joint movements), cam and lever systems, RBR and SLSC resistance. The descriptive analysis of RBR, SLSC and PnR provides the strength and conditioning coach and clinician with a methodology to quantify variable resistance, which may be useful in the presc1iption of specific loading intensities. The RBR bands exhibited curvilinear tension-defonnation relationships and were best represented by quadratic function equations (R2 2: 0.99); while the SLS chains exhibited linear mass-displacement relationships and were best represented by linear function equations (R2 = 1). When purchasing bands the buyer needs to be aware of inter-band resting length differences (0.5 to 5.3%), as this results in mean tension imbalances (1.6 to 17.5%) in the same colour band. The development of adjustment equations were required for the PnR system to correct for the inaccuracies of the displayed values. The displayed and measured (i.e. force plate) loads increased in a linear fashion allowing the regression equations to accurately predict (r2 = 1) true loads from displayed load values. The mean displayed load was 28% greater than the mean measured load, which would pose a major problem for prescribing specific pneumatic loads if adjustment equations were unavailable. All pneumatic resistive devices should be tested by the manufacturer, practitioner and scientist in a similar manner if utilized in institutes of sport and research, as well as fitness centres.
The experimental study was undertaken to determine the mechanical effects of CR, RBR, SLSC and PnR on peak velocity (PV), mean force (MF), peak force (PF), work, mean power (MP), peak power (PP), rate of force development (RFD) and rate of power development (RPD) while performing h·aditional squats (TS), shallow counte1movement jumps (SCMJ) and deep countennovement jumps (DCMJ). Nine resistance-trained male participants (age 25.8 ± 4.7 years; height 178.9 ± 7.3 cm; mass 81.4 ± 8.4 kg) completed a total of eight sessions, which were comprised of four familiarization and four testing sessions. The significant differences found between the resistance modes suggest that strength and conditioning professionals should use RBR bands and PnR in training programs to increase speed and power in their athletes; and utilize CR and PnR to maximize force and power development. Based on current findings the use of SLS chains for training ballistic movements is not recommended.
LCSH Subject Headings
Isometric exercise -- Physiological aspects.
Exercise -- Equipment and supplies.
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McMaster, D. T. (2009). Effect of resistance mode on squat and jump kinematics and kinetics. Retrieved from http://ro.ecu.edu.au/theses/1892