Peripheral Nerve Responses to Muscle Stretching: A Systematic Review

Area of Science:

• Neuroscience
• Sports Medicine
• Physiotherapy

Background:

• Stretching commonly targets muscle-tendon units for flexibility.
• Limited research exists on stretching's effects on peripheral nerves within muscles.

Purpose of the Study:

• To investigate and elucidate peripheral nerve responses to stretching protocols.
• To synthesize current evidence on nerve stiffness, displacement, and pain thresholds post-stretching.

Main Methods:

• Systematic literature search across Scopus, PubMed, and ScienceDirect databases.
• Inclusion of 10 studies with fair to good methodological quality (NHLBI tool).
• Analysis of outcomes including nerve stiffness, displacement, pain pressure thresholds, and resistive torque.

Main Results:

• Stretching led to decreased nerve stiffness (-15.6%) and increased pain pressure thresholds (-1.9kg).
• Nerve displacement and deformation were frequently observed across different movement planes.
• High heterogeneity in stretching protocols was noted among the included studies.

Conclusions:

• Peripheral nerve responses to muscle stretching include reduced nerve stiffness and elevated pain pressure thresholds.
• Nerve displacement is a common finding, but its clinical significance remains unclear.
• A lack of longitudinal studies hinders understanding of long-term peripheral nerve adaptations to stretching.