calves

Purpose: Balance-challenging exercise has stronger evidence for fall prevention than resistance training alone, but most resistance-training protocols evaluated to date have omitted ankle plantarflexor exercises.This pilot randomized controlled trial examined the feasibility of a full-scale trial comparing machine-based resistance training (MRT) including calf raises with unstable balance training (UBT), and explored preliminary change patterns in fall-related functional outcomes among middle-aged women.Methods: Ten women aged 45-64 from Seoul were randomized 1:1 to MRT (n=5) or UBT (n=5); one UBT participant withdrew before baseline (n=9 analyzed).Both groups completed 12 sessions over 6 weeks (60 minutes, 2×/week).MRT used six machine-based exercises with calf raises; UBT used five unilateral unstable-surface exercises.Feasibility (recruitment, retention, attendance, adverse events), body composition, balance (Timed Up and Go, single-leg stance, Y-balance), and isokinetic knee strength were assessed.Within-group change was described using Hedges' g as exploratory signals.Results: Feasibility was supported by 90% retention, ≥ 90% attendance, and no serious adverse events.Withingroup patterns showed MRT with a larger Y-balance change (g=＋1.60)and UBT with a larger Timed Up and Go change (g=-0.96).Both groups reduced body fat and improved knee-flexor total work.Single-leg-stance results were limited by ceiling effect (eyes open) and baseline-variance artifact (eyes closed).All effect-size estimates are exploratory; no between-group inference is warranted.Conclusion: A future non-inferiority trial appears feasible with approximately 35 participants per arm as an initial planning estimate, pending refinement of variance and incorporation of stratified randomization on baseline blood pressure.

matched text: “calf”

Introduction Muscle-tendon unit interactions are crucial for efficient walking but remain unstudied in adult-onset spastic paresis. This cross-sectional study evaluated the relative contributions of the Achilles tendon, muscle fascicles, and muscle belly to the dynamics of the gastrocnemius medialis during gait in individuals with stroke and incomplete spinal cord injury, focusing on Equinus and Non-equinus patterns. Methods Sixty participants (20 with stroke, 18 with incomplete spinal cord injury, 22 healthy controls) underwent 3-dimensional gait analysis synchronized with ultrasound. Participants were stratified into “Equinus” ( N = 19) and “Non-equinus” ( N = 19) groups based on terminal stance ankle dorsiflexion. The force-length relationship (maximal torque, T max ; optimal fascicle length, L opt ) of the gastrocnemius medialis was determined on an isokinetic dynamometer using supramaximal tibial nerve stimulation. Muscle-tendon unit, belly, and tendon kinematics were calculated throughout the gait cycle. Results T max was reduced in both pathological groups, but L opt was significantly shorter only in the Equinus group ( P < 0.001). During walking, both pathological patterns showed a disruption of the spring-like mechanism (loss of fascicle-tendon decoupling). The Non-equinus pattern was characterized by significantly longer tendons and reduced muscle-tendon unit excursion. Critically, fascicles in both pathological groups operated beyond the optimal length of the force-length curve during stance. Conclusion Adaptive gait patterns in adult spastic paresis are primarily discriminated by tendon adaptations rather than muscle belly dynamics. The observed functional paradox (structurally short muscles operating in an over-stretched state during stance) highlights a biomechanical trade-off for surgical tendon lengthening. Such intervention may be detrimental to muscle force-generating capacity by shifting fascicles further onto the descending limb of the force-length relationship. These findings suggest that personalized assessments could help optimize clinical decisions, including the development of therapeutic strategies designed to restore tendon stiffness and improve force-transmission efficiency. ClinicalTrials NCT06474117.

matched text: “gastrocnemius”