Joint torque and electromyographic activity during eccentric exercise for hip adductors at different hip flexion...

Area of Science:

• Biomechanics
• Sports Medicine
• Exercise Physiology

Background:

• Hip adductor strength is crucial for athletic performance and injury prevention.
• Understanding the influence of hip joint angles on eccentric adductor function is important for training.
• Previous research has not fully elucidated the impact of hip flexion on eccentric adductor strength and muscle activation.

Purpose of the Study:

• To examine the effects of three hip flexion angles (0°, 45°, 90°) on eccentric hip adduction.
• To investigate the influence of leg dominance on these parameters.
• To assess peak joint torque, angle at peak torque, and peak electromyographic activity (EMGA) of the adductor longus.

Main Methods:

• Sixteen recreationally active participants performed bilateral eccentric hip adduction at 0°, 45°, and 90° hip flexion.
• A custom-built dynamometer was used to measure peak adduction torque and angle at peak torque.
• Peak electromyographic activity (EMGA) of the adductor longus was recorded.

Main Results:

• Peak adduction torque was significantly lower at 90° hip flexion compared to 0° and 45° (p < 0.01).
• No significant differences in peak torque or EMGA were found based on leg dominance.
• Hip flexion angle and leg dominance did not significantly affect the angle at peak torque or peak EMGA.

Conclusions:

• Eccentric hip adduction strength is reduced in a 90° flexed hip position, likely due to biomechanical factors.
• Neural activation of the adductor longus remains consistent across tested hip flexion angles.
• Training programs for adductor strength and injury prevention may benefit from utilizing hip positions with less flexion.