Neurophysiological Mechanisms Underpinning Stretch-Induced Force Loss

Area of Science:

• Neuroscience
• Exercise Physiology
• Muscle Physiology

Background:

• Prolonged passive muscle stretch is known to reduce maximal muscle force production.
• Emerging evidence indicates that neural adaptations significantly contribute to this stretch-induced force reduction.

Purpose of the Study:

• To review existing literature and present new evidence on acute neurophysiological changes following passive muscle stretching.
• To explore the roles of supra-spinal and spinal structures in the force reduction observed after passive muscle stretch.

Main Methods:

• Literature review of studies investigating neurophysiological responses to passive muscle stretching.
• Analysis of new evidence concerning acute changes in the nervous system after stretching protocols.

Main Results:

• Passive muscle stretching induces acute neurophysiological changes.
• Both supra-spinal and spinal neural structures are implicated in the force reduction mechanism.
• Evidence suggests a disfacilitation at the motoneuronal level post-stretching.

Conclusions:

• A novel hypothesis proposes that motoneuronal disfacilitation after passive muscle stretch is a primary cause of reduced neural drive.
• This disfacilitation significantly impacts the muscle's capacity for maximal force production.