Mechanical power and muscle action during forward and backward running

Area of Science:

• Biomechanics
• Exercise Physiology
• Rehabilitation Science

Background:

• Increasing interest in backward running (BR) for exercise and rehabilitation.
• Lack of studies combining electromyography (EMG) and joint kinetics for BR analysis.

Purpose of the Study:

• Compare EMG and kinetic parameters during the stance phase of forward running (FR) and BR.
• Analyze the sagittal plane of the right knee in male subjects during FR and BR.

Main Methods:

• Utilized 60-Hz video cameras for motion data and a link segment model of the lower extremity.
• Collected synchronized force plate and 1000-Hz EMG data from key knee and lower leg muscles.
• Calculated peak and total mechanical power and work at the knee.

Main Results:

• Significantly less peak power and total work at the knee during BR compared to FR (p < 0.05).
• Observed significant differences in muscle firing patterns between FR and BR conditions (p < 0.05).
• Vastus lateralis (VL) and vastus medialis oblique (VMO) exhibited isometric and concentric action during BR, contrasting with FR.

Conclusions:

• BR requires less knee power and work than FR.
• BR effectively induces isometric and concentric muscle action in the VL and VMO.
• BR may be beneficial for clinical conditions needing enhanced knee extensor strength.