Effects of Virtual Reality Versus Whole-Body Vibration on Muscle Strength and Balance in Children with Duchenne Muscular Dystrophy: a Randomized Controlled Trial.

Abstract

ObjectiveTo compare the effects of virtual reality versus whole-body vibration on quadriceps muscle strength and balance in children with Duchenne muscular dystrophy.MethodsIn this assessor-blinded, parallel-group randomized controlled trial (1:1 allocation), 50 ambulatory boys with DMD (aged 6-10 years; AFCSD levels I-II) were recruited from Cairo University's outpatient clinic. Both groups received a structured physical therapy program (warm-up, stretching, isometric contractions) three times weekly for 12 weeks. VR Group (n = 25) additionally performed 10 min of semi-immersive VR (Nintendo Wii Fit Balance Board). WBV Group (n = 25) additionally performed 10 min of side alternating WBV (30 Hz, 2 mm amplitude). The primary outcome was isometric quadriceps strength (Lafayette manual muscle tester). Secondary outcomes were overall stability index (OSI), anterior-posterior stability index (APSI), and medial-lateral stability index (MLSI) measured by the Biodex Balance System. Assessments were conducted at baseline, 6 weeks, and 12 weeks by assessors blinded to group allocation. A mixed MANOVA with Bonferroni correction was used.ResultsA significant treatment time interaction was observed (F = 22.31, p < 0.001, ηp²=0.85). At 12 weeks, the VR group showed significantly greater improvements than the WBV group in right quadriceps strength (p < 0.001, ηp²=0.742), left quadriceps strength (p < 0.001, ηp²=0.757), OSI (p < 0.001, ηp²=0.346), APSI (p < 0.001, ηp²=0.737), and MLSI (p < 0.001, ηp²=0.335). No adverse events were reported.ConclusionIn ambulatory children with DMD, a 12-week VR-based intervention produced greater improvements in isometric quadriceps strength and dynamic postural stability compared to WBV. These findings support VR as a motivating adjunct to physical therapy, though functional outcomes and longer follow-up are needed.