Consider a point guard trying to shoot a layup. As they move toward the net, the sensorimotor system is charged with controlling infinite degrees of freedom while perceiving the evolving environment. Like all athletic actions, this requires coordination of distributed groups of muscles and joints. 

A few studies investigating this concept of within-person coordination in individuals with ACL reconstruction characterize less adaptability of joint coordination during single-limb balance, with higher rigidity indicating higher re-injury risk. The same pattern of less variable joint coordination is true of gait as well. Unfortunately, these impairments are less clinically tangible than muscle weakness or range of motion restriction. What modifiable factors contribute to these impairments? How can we be sure we are addressing them?

Speculative, but inability to adapt or modulate performance likely stem from impairments in motor-planning. 

Clinical tip: Use neurocognitive training (e.g., choice reaction time) to target this and incorporate principles of motor-learning (e.g., random practice) into rehabilitation.

Refs:

1. Paterno MV, Kiefer AW, Bonnette S, et al. Prospectively identified deficits in sagittal plane hip-ankle coordination in female athletes who sustain a second anterior cruciate ligament injury after anterior cruciate ligament reconstruction and return to sport. Clin Biomech (Bristol, Avon). 2015;30(10):1094-1101.

2. Kiefer AW, Ford KR, Paterno MV, et al. Inter-segmental postural coordination measures differentiate athletes with ACL reconstruction from uninjured athletes. Gait Posture. 2013;37(2):149-153.