Resistance strength training exercise in children with spinal muscular atrophy.

INTRODUCTION: Preliminary evidence in adults with spinal muscular atrophy (SMA) and in SMA animal models suggests exercise has potential benefits in improving or stabilizing muscle strength and motor function. METHODS: We evaluated feasibility, safety, and effects on strength and motor function of a home-based, supervised progressive resistance strength training exercise program in children with SMA types II and III. Up to 14 bilateral proximal muscles were exercised 3 times weekly for 12 weeks. RESULTS: Nine children with SMA, aged 10.4 ± 3.8 years, completed the resistance training exercise program. Ninety percent of visits occurred per protocol. Training sessions were pain-free (99.8%), and no study-related adverse events occurred. Trends in improved strength and motor function were observed. CONCLUSIONS: A 12-week supervised, home-based, 3-day/week progressive resistance training exercise program is feasible, safe, and well tolerated in children with SMA. These findings can inform future studies of exercise in SMA.

Reliability and validity of the TIMPSI for infants with spinal muscular atrophy type I.

PURPOSE: This study examined the reliability and validity of the Test of Infant Motor Performance Screening Items (TIMPSI) in infants with type I spinal muscular atrophy (SMA). METHODS: After training, 12 evaluators scored 4 videos of infants with type I SMA to assess interrater reliability. Intrarater and test-retest reliability was further assessed for 9 evaluators during a SMA type I clinical trial, with 9 evaluators testing a total of 38 infants twice. Relatedness of the TIMPSI score to ability to reach and ventilatory support was also examined. RESULTS: Excellent interrater video score reliability was noted (intraclass correlation coefficient, 0.97-0.98). Intrarater reliability was excellent (intraclass correlation coefficient, 0.91-0.98) and test-retest reliability ranged from r = 0.82 to r = 0.95. The TIMPSI score was related to the ability to reach (P ≤ .05). CONCLUSION: The TIMPSI can reliably be used to assess motor function in infants with type I SMA. In addition, the TIMPSI scores are related to the ability to reach, an important functional skill in children with type I SMA.