Lower extremity joint kinetics and energetics during backward running.

Area of Science:

• Biomechanics
• Human Movement Science
• Sports Science

Background:

• Understanding the biomechanics of backward running is crucial for optimizing training and injury prevention.
• Previous research has focused on forward running, leaving a gap in knowledge regarding backward locomotion.

Purpose of the Study:

• To quantify lower extremity joint moments and muscle powers during backward running.
• To compare the biomechanical demands of backward versus forward running.

Main Methods:

• High-speed sagittal plane film analysis (100 Hz) and ground reaction force data (1000 Hz) were collected from five male runners performing backward running.
• Inverse dynamics calculations were used to determine joint moments and powers, normalized to body mass for comparison.

Main Results:

• Backward running exhibited hip moment and power patterns similar in magnitude but opposite in direction to forward running.
• Knee extensors were the primary propulsive force in backward running, with greater moment and power output than ankle plantarflexors.
• Ankle plantarflexors served as primary shock absorbers, generating significant negative power during early stance in backward running.

Conclusions:

• The functional roles of knee and ankle muscles are interchanged between backward and forward running.
• Backward running places greater emphasis on knee extensor torque, supporting its role in enhancing knee extensor strength.
• Backward running demonstrates distinct lower extremity joint power and moment profiles compared to forward running.