Clinical Pilates in Practice: Closed Kinetic Chains & Motor Control
In the author’s words:
"This commentary encourages the study of mobility both as a potential explanation for different motor control strategies and as a useful concept for comparing otherwise seemingly disparate musculoskeletal systems.” (p.7).
Olsen, Aaron M. "A mobility-based classification of closed kinematic chains in biomechanics and implications for motor control." The Journal of Experimental Biology 222, no. 21 (2019), jeb195735. doi:10.1242/jeb.195735.
Key Points: Closed Kinetic Chains & Motor Control
Closed-kinetic-chains have fewer degrees of freedom than open-kinetic chains.
There is a trade-off between stability with a closed kinematic chain vs mobility with an open kinematic chain (increased degrees of freedom).
An isometric muscle contraction can conditionally decrease the mobility of a CKC; this is controlled neurally (vs the mechanical nature of a ligament becoming taut or slack).
Passive/accessory movements play a role in mobility, as motion observed is a combination of movements.
Clinical Pilates in Practice
Be aware of how pseudo-closed kinematic chains will change degrees of freedom through the necessity of an isometric muscle contraction.
→ Feet in straps/leg springs.
→ Hands in straps.
Joint position in a CKC will affect ligament length, and thus the degrees of freedom available for movement.
→ When cueing knee alignment for footwork on the Reformer, note that the collaterals are taut in lateral tibial rotation but this will not be true if there is a ligamentous injury.
Cueing can help to elicit an appropriate muscular contraction for stability around a joint. If the contraction is too strong/inappropriate for the force input, this can irradiate and decrease mobility at other joints.
If accessory mobility (rolling, gliding, sliding) is limited, it will affect overall movement quality (CKC and OKC).
→ If necessary and appropriate, use manual therapy to address restrictions – it’s okay to use your other tools!