Three-dimensional hip and knee loading during the Copenhagen adductor exercise

Area of Science:

• Biomechanics
• Sports Medicine
• Human Movement Science

Background:

• The Copenhagen adductor exercise (CAE) is widely used for strengthening groin muscles.
• Groin muscles primarily act in the frontal plane, but also contribute to sagittal and transverse plane movements.
• This suggests the CAE imposes three-dimensional (3D) muscular demands on the hip and knee joints.

Purpose of the Study:

• To quantify the three-dimensional (3D) hip and knee joint loading during variations of the Copenhagen adductor exercise (CAE).
• To investigate the influence of support stand location on joint loading during the CAE.

Main Methods:

• Eleven men and 13 women performed the CAE with the support stand positioned at the knee, ankle, and midway.
• Ground reaction forces and marker trajectories were recorded to calculate hip and knee net joint moments (NJM).

Main Results:

• Hip adductor net joint moments (NJM) were significantly larger with ankle support compared to knee support.
• More distal support locations resulted in greater hip extensor NJM.
• Support locations distal to the knee elicited knee adductor and flexor NJM.
• Hip and knee sagittal plane NJMs correlated strongly with transverse plane thigh and shank orientations.

Conclusions:

• The Copenhagen adductor exercise (CAE) engages frontal and sagittal plane muscle actions at the hip and knee.
• Increasing the distal support location amplifies these muscle efforts.
• Understanding these 3D joint demands is crucial for optimizing CAE for rehabilitation and training.