Mitigating Neural Hypoexcitability and Weakness During Disuse in Women

Summary

Clinical trial The goal of this clinical trial is to learn how muscle weakness and atrophy develop during short periods of arm immobilization and whether a type of exercise called cross-education can help reduce these effects in women at midlife. The main questions it aims to answer are: What changes happen in the nervous system that lead to weakness when a wrist is immobilized? Can training the opposite arm help maintain muscle strength, muscle size, and nervous system function in the immobilized arm? Researchers will compare women who have their wrist immobilized with or without opposite-arm resistance training. Participants will: Wear a wrist cast on one arm for 7 days Complete strength training with the opposite arm or no training, depending on their group Attend study visits for strength and nervous system testing Have non-invasive tests (like magnetic brain stimulation, muscle recordings, and muscle imaging) to measure how the nervous system and muscle responds

Detailed Description

This clinical trial employs a two-phase, parallel-group randomized controlled design targeting midlife women (ages 40-65), stratified by menopausal status. Participants will be randomized to either a cross-education training group (TRAIN) or a standard care control group (CONTROL). Phase 1 (Immobilization and Cross-Education Intervention): To induce rapid declines in neuromuscular function, participants will undergo unilateral wrist immobilization of the non-dominant arm using a hard cast for 7 days. During this period, the TRAIN group will complete three resistance training sessions with the non-immobilized arm, while the CONTROL group will remain inactive. The intervention protocol emphasizes maximal effort contractions. The protocol was developed from prior laboratory work and proof-of-concept interventions, with the goal of maximizing the cross-education response. Phase 2 (Rehabilitation and Recovery): Following cast removal, both groups will complete a 2-week standardized rehabilitation program (3 sessions per week) designed to restore wrist strength and function in the previously immobilized arm. Rehabilitation training includes progressive resistance exercise to target recovery of neuromuscular performance.

Eligibility Criteria

Interventions