Acute Responses of Postural Alignment, Kinematic Synergy, and Intermuscular Coherence to Postural Muscle Facilitation (Retrospective)

Acute Responses of Postural Alignment, Kinematic Synergy, and Intermuscular Coherence to Postural Muscle Facilitation (Retrospective)

Postural alignment is often intervened upon in health, fitness, and physical medicine settings. Despite a long tradition in this area, current notions of optimal or normal posture are superficial and often logically inconsistent. A recent attempt to reconcile diverging opinions about good posture proposes that alignment be considered in relation to individual joints' natural tendencies to collapse under gravity. This theory allows different maladaptive postures to be described in terms of functional deficits and compensatory adaptations at the muscular level. Working within this type of theory, postural interventions may be able to account for comparative advantages in maintaining alignment between different muscle systems. This would represent a step forward from current practices, which usually attempt to force arbitrary alignment patterns indiscriminately.

The current study presents motion capture and electromyography (EMG) data evaluating the effects of two interventions on individual participants' bipedal standing alignment patterns with respect to the gravitational collapsing tendencies referenced above. Additional outcomes included functional grouping of muscle activation signals (via intermuscular coherence) and kinetic chain continuity. The interventions include 1) an experimental intervention purported to engage muscles that naturally resist the collapsing effects of gravity, and 2) a control intervention designed to inhibit other muscle groups that are sometimes involved in maintaining bipedal alignment in a compensatory role. Study outcomes are measured before and after both interventions to quantify the acute effects of each. All participants complete both interventions in random order, crossing over after a one-week washout period. This research will provide insight into the acute effects of studied interventions, specifically those relating to maintenance of bipedal alignment with respect to gravitational collapsing tendencies.

Inclusion Criteria:

• Healthy adult
• 18 - 40 years of age

Exclusion Criteria:

• Recent (< 6 months) history of lower extremity injury
• Recent (< 6 months) history of other musculoskeletal or neurological disorder affecting balance
• Contraindications to participation in physical activity