Training, Competition & Health

Abstract

Problem: Since segment lengths of the lower extremities influence joint kinematics in multi-joint movements, anthropometric standardization seems necessary to study the force-length-velocity relationships of muscles in vivo. Mathematical approaches to calculate the needed linear velocities for the desired angular kinematics from individual anthropometric data exist and are in use. Nevertheless, this approach does not account for possible shifts due to cushion padding and soft tissue compression.Methods: 38 physical education students (31 male, 7 female, 244.32 years, 175.937.92 cm, 74.9310.86 kg) participated in this investigation. Knee-angles and angle-specific force during multi-joint isokinetic leg extensions derived from an anthropometric model were compared to corresponding knee angles and forces derived from optical marker tracking for two different linear velocities (0.1 m/s and 0.7 m/s).Results: The results show significant differences (p < 0.05) in knee angles and angle-specific forces for multi-joint isokinetic leg extensions with 0.1 m/s and no significant differences for movements with 0.7 m/s.Discussion: Studies investigating force-length-velocity relationships during multi-joint leg extensions should implement optical measurement to eliminate the effects of shifts due to cushion padding and soft tissue compression especially when working with slow linear velocities. The possibility of a device-specific correction for the anthropometric model should be addressed in further research.Key Words: Strength Testing, Force-Length Relationship, Force-Velocity Relationship