Quantitative ultrasound of submental and masticatory muscles in children with cerebral palsy.

PURPOSE: Quantitative muscle ultrasound (QMUS) is potentially valuable as a diagnostic tool in central neurological disorders, as it provides information about changes in muscle architecture. This study aimed to investigate whether ultrasound images of the submental and masticatory muscles in children with spastic cerebral palsy (CP) differ from those obtained in a reference group, and whether observed ultrasound abnormalities differ between subgroups of children with different Eating and Drinking Ability Classification System (EDACS) levels to support its construct validity. METHODS: A prospective cohort study was conducted in 25 children with spastic CP aged 3-18 years. QMUS of selected muscles was performed. Muscle thickness and echogenicity in the CP group were compared to previously collected reference values, and between different EDACS levels within the CP group. RESULTS: Median echogenicity of all muscles was significantly higher in children with CP than in healthy controls. The temporalis muscle was significantly thinner in the CP group. There were no differences in muscle thickness or echogenicity between EDACS levels. CONCLUSION: QMUS is able to detect abnormal architecture of submental and masticatory muscles in children with spastic CP, but the interpretation of abnormalities in relation to the severity of mastication and swallowing problems needs further investigation.

Efficacy of Walking Adaptability Training on Walking Capacity in Ambulatory People With Motor Incomplete Spinal Cord Injury: A Multicenter Pragmatic Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Balance and walking capacity are often impaired in people with motor incomplete spinal cord injury (iSCI), frequently resulting in reduced functional ambulation and participation. This study aimed to assess the efficacy of walking adaptability training compared to similarly dosed conventional locomotor and strength training for improving walking capacity, functional ambulation, balance confidence, and participation in ambulatory people with iSCI. METHODS: We conducted a 2-center, parallel-group, pragmatic randomized controlled trial. Forty-one people with iSCI were randomized to 6 weeks of (i) walking adaptability training (11 hours of Gait Real-time Analysis Interactive Lab (GRAIL) training-a treadmill in a virtual reality environment) or (ii) conventional locomotor and strength training (11 hours of treadmill training and lower-body strength exercises). The primary measure of walking capacity was maximal walking speed, measured with an overground 2-minute walk test. Secondary outcome measures included the Spinal Cord Injury Functional Ambulation Profile (SCI-FAP), the Activities-specific Balance Confidence (ABC) scale, and the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P). RESULTS: No significant difference in maximal walking speed between the walking adaptability (n = 17) and conventional locomotor and strength (n = 18) training groups was found 6 weeks after training at follow-up (-0.05 m/s; 95% CI = -0.12-0.03). In addition, no significant group differences in secondary outcomes were found. However, independent of intervention, significant improvements over time were found for maximal walking speed, SCI-FAP, ABC, and USER-P restrictions scores. Conclusions. Our findings suggest that walking adaptability training may not be superior to conventional locomotor and strength training for improving walking capacity, functional ambulation, balance confidence, or participation in ambulatory people with iSCI. TRIAL REGISTRATION: Dutch Trial Register; Effect of GRAIL training in iSCI.

Age-related changes in muscle coordination patterns of stepping responses to recover from loss of balance.

INTRODUCTION: Reactive stepping capacity to recover from a loss of balance declines with aging, which increases the risk of falling. To gain insight into the underlying mechanisms, we investigated whether muscle coordination patterns of reactive stepping differed between healthy young and older individuals. METHODS: We performed a cross-sectional study between 15 healthy young and 14 healthy older adults. They recovered from 200 multidirectional platform translations that evoked reactive stepping responses. We determined spatiotemporal step variables and used muscle synergy analysis to characterize stance- and swing-leg muscle coordination patterns from the start of perturbation until foot landing. RESULTS: We observed delayed step onsets in older individuals, without further spatiotemporal differences. Muscle synergy structure was not different between young and older individuals, but age-related differences were observed in the time-varying synergy activation patterns. In anterior-posterior directions, the older individuals demonstrated significantly enhanced early swing-leg synergy activation consistent with non-stepping behavior. In addition, around step onset they demonstrated increased levels of synergy coactivation (mainly around the ankle) in lateral and anterior directions, which did not appear to hamper foot clearance. CONCLUSION: Although synergy structure was not affected by age, the delayed step onsets and the enhanced early synergy recruitment point at a relative bias towards non-stepping behavior in older adults. They may need more time for accumulating information on the direction of perturbation and making the corresponding sensorimotor transformations before initiating the step. Future work may investigate whether perturbation-based training improves these age-related deficits.