Electrically evoked isokinetic plantar flexor torque in males

Area of Science:

• Biomechanics
• Human Physiology
• Kinesiology

Background:

• Understanding muscle torque-velocity relationships is crucial for biomechanical analysis.
• Isokinetic dynamometry is a standard tool for measuring joint torques.
• Accurate measurement requires precise control of muscle activation and instrument dynamics.

Purpose of the Study:

• To measure angle-specific isokinetic plantar flexor torques in young males.
• To characterize the torque-velocity relationship of the triceps surae muscle.
• To model the relationship using an exponential equation.

Main Methods:

• Seven male subjects (18-21 years) participated.
• A modified Cybex II isokinetic dynamometer with a strain-gauge load cell was used.
• Supramaximal electrical stimulation ensured maximal triceps surae activation at velocities from 0.5 to 5.0 rad/s.

Main Results:

• Plantar flexor torque decreased non-linearly as angular velocity increased.
• The torque-velocity data was well-described by the exponential equation V = a(e-1/b - e-Po/b).
• The mean intrasubject coefficient of variation for torque was 7.9 ± 1.88%.

Conclusions:

• The study provides a quantitative model for the plantar flexor torque-velocity relationship.
• The modified dynamometer demonstrated good reliability for measuring isokinetic torques.
• Findings contribute to understanding lower limb muscle function during dynamic movements.