Greater Gastrocnemius Muscle Hypertrophy After Partial Range of Motion Training Performed at Long Muscle Lengths.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 37015016 · doi:10.1519/JSC.0000000000004460
What was done
Forty-two young women completed an 8-week resistance training program (3 sets of 15-20 RM, 3 days/week) using calf raises on a horizontal leg-press machine. Participants were randomized to 1 of 3 range of motion (ROM) conditions: FULL ROM (ankle: -25° to +25°), INITIAL ROM (long muscle length partials: -25° to 0°), or FINAL ROM (short muscle length partials: 0° to +25°), where 0° was defined as 90° between the foot and tibia. Medial and lateral gastrocnemius muscle thickness changes were measured via B-mode ultrasound.
What was found
INITIAL ROM produced significantly greater medial gastrocnemius growth (+15.2%) than FULL ROM (+6.7%) and FINAL ROM (+3.4%) (p ≤ 0.009). For lateral gastrocnemius, INITIAL ROM (+14.9%) produced significantly greater growth than FINAL ROM (+6.2%, p < 0.024), but did not differ significantly from FULL ROM (+7.3%, p = 0.060).
Why it matters
This study provides direct experimental evidence that training muscles at longer muscle lengths can accelerate hypertrophy compared to full or shortened ranges of motion.
Limits
The sample was limited to young women over an 8-week period, leaving generalizability to men, older adults, and longer training horizons uncertain. The per-group sample size was small (14 per arm), and the abstract does not detail nutritional controls, participant training status, or blinding of ultrasound assessors.
Cited by
- supports Emerging scientific evidence indicates that seated calf raises and top squeeze contractions provide little benefit for hypertrophy, whereas calf muscles respond effectively to stretch and lengthened partials.