Inter-joint coordination and lower limb support in those with ACL-reconstruction

Area of Science:

• Biomechanics
• Orthopedics
• Movement Science

Background:

• Individuals with anterior cruciate ligament reconstruction (ACLR) exhibit altered gait patterns.
• Support demands are shifted away from the surgical knee, potentially requiring compensatory ankle or hip actions.

Purpose of the Study:

• To compare lower-limb support and inter-joint coordination during walking in individuals with ACLR.
• To understand how ACLR patients adapt and coordinate movements to redistribute support demands.

Main Methods:

• Evaluated treadmill walking in 28 individuals with ACLR and 20 healthy controls at preferred speed.
• Calculated total support moment (TSM) and individual joint contributions using sagittal joint moments.
• Assessed inter-joint coordination (ankle-knee, knee-hip) using vector coding during stance phases.

Main Results:

• The ACLR limb showed a smaller first peak TSM and greater hip contributions (6%) compared to the contralateral limb.
• ACLR limbs exhibited increased ankle motion in early/mid-stance and hip motion in mid-late stance.
• Coordination alterations included increased reliance on ankle and knee motions to compensate for knee mechanics.

Conclusions:

• Individuals with ACLR demonstrate altered joint coordination strategies during walking.
• These strategies involve increased ankle and hip contributions to manage support and propulsion demands.
• Altered coordination may reduce muscular requirements on the surgical limb post-ACLR.