Alternative instrument for the evaluation of handgrip strength in Duchenne muscular dystrophy.

BACKGROUND: The commonly used dynamometers can be ineffective in evaluating handgrip in patients with Duchenne muscular dystrophy (DMD), especially children with generalized muscle weakness. The aim of this study was to analyze whether the modified sphygmomanometer is an effective instrument for handgrip strength evaluation in patients with DMD, during different stages of the disease. METHOD: The handgrip strength of 33 patients was evaluated by the Jamar dynamometer and the modified sphygmomanometer. Motor function was evaluated by the Motor Function Measurement (MFM) scale. Four evaluations, with a six-month interval between each, were performed: Evaluation 1 (N = 33), Evaluation 2 (N = 24), Evaluation 3 (N = 15), and Evaluation 4 (N = 8). A linear regression model with mixed effects was used for the longitudinal data and descriptive analysis of strength for all four evaluations. RESULT: The first evaluation data presented very high correlations between the dynamometer and the modified sphygmomanometer (r = 0.977; p < 0.001). The longitudinal analysis showed a significant difference between Evaluation 1 and the other handgrip strength evaluations obtained using the dynamometer (p < 0.05) but not the modified sphygmomanometer (p > 0.05). Null values were obtained only when using the dynamometer device. CONCLUSION: The modified sphygmomanometer seems to be more suitable than the dynamometer for measuring handgrip strength in all stages of DMD.

The Use of a Wheelchair Propulsion Field Test to Determine Peak Heart Rate in Children and Adolescents With Myelomeningocele.

PURPOSE: We analyzed the evolution and pattern of heart rate (HR) during the 12-minute wheelchair propulsion field test (WPFT) and compared the peak HR (HRpeak) from the WPFT to the HRpeak obtained in the progressive cardiopulmonary exercise test on arm cranking ergometer (ACT). We aimed to determine if the field test detects the HRpeak consistently and could be used in clinical practice. METHODS: Eleven wheelchair-using children and adolescents with myelomeningocele (aged 8-15 y) performed a maximal ACT and a 12-minute WPFT. HR was recorded continuously at rest, during each minute of the tests, and at recovery. Mixed analysis of variance was used to compare the variables at rest and peak. Bland-Altman plot and Lin's concordance correlation coefficient were used to show agreement between the tests. RESULTS: During minute 2 of the WPFT, participants reached 73%-96% of the HRpeak values recorded in the ACT. From minutes 4 to 12, participants reached HRpeak values ranging 86%-109% of the values recorded in the ACT. There is agreement between the ACT and the WPFT tests. CONCLUSION: WPFT with minimal duration of 4 minutes may be an alternative tool to obtain HRpeak in children and adolescents with myelomeningocele.

Beneficial effects of ankle-foot orthosis daytime use on the gait of Duchenne muscular dystrophy patients.

BACKGROUND: Orthosis use prevents muscle contracture and prolongs ambulation in patients with Duchenne muscular dystrophy (DMD). However, its biomechanical effects on gait are unclear. This study assessed the effects of daytime and night-time use of Articulated Ankle Foot Orthosis (AFO) on kinematic, kinetic and spatial/temporal gait parameters of DMD patients. METHODS: Twenty ambulatory patients (4-12years of age) were assigned to one of three groups: no orthosis (NoO; n=7), night-time orthosis (NiO; n=7), day-time orthosis (DO; n=6). All subjects were evaluated once (Ev1) and five of them were re-evaluated between five and seven months after Ev1 (Ev2). FINDINGS: Cross-sectional analysis with linear mixed-effects models (ANOVA) showed increased peak dorsiflexion angle and dorsiflexor moment and decreased plantar flexion angle and ankle joint power generation for the DOwith group when compared to the NoO group (P<0.05). The DOwith group also showed decreased peak hip flexion angle, hip power absorption, plantar flexion angle and increased peak dorsiflexion moment when compared to the NoO group (P<0.05). Analysis of gait cycle curves showed significant and clinically relevant changes in kinematic and kinetic parameters for the DOwith group when compared to the other experimental groups. Longitudinal analysis suggest that night-time use of Articulated AFO can promote positive changes in gait parameters of DMD patients, when used before the functional deficit is too advanced. INTERPRETATION: Early daytime and night-time use of Articulated AFO changed gait and minimized typical compensations seen in DMD patients, thus it is recommended in order to prolong gait ability.

Normative data for hand grip strength in healthy children measured with a bulb dynamometer: a cross-sectional study.

OBJECTIVE: To present the normative hand grip strength values measured with a bulb dynamometer for children, by gender and age, and to correlate the findings with weight, height, body composition and handedness. DESIGN: Cross-sectional study. PARTICIPANTS: Data from 295 healthy children of both genders aged 6 to 13 years were analysed. METHODS: Weight, height, body composition (Biodynamics model 450 bioimpedance analyser), handedness (Edinburgh scale) and grip strength measured with a bulb dynamometer (North Coast) were obtained. RESULTS: Grip strength of both hands increased with age in the two genders. Grip strength was similar in boys and girls between 6 and 13 years of age. The dominant hand was stronger than the non-dominant hand [mean (standard deviation) 7.0 (2.3)psi vs 6.5 (2.1)psi], with a mean difference of 0.52psi (95% confidence interval of the difference 0.46 to 0.58). Grip strength was positively correlated with fat-free mass and height (r≥0.75). CONCLUSION: This study provides normative values for hand grip strength measured with a bulb dynamometer in children aged 6 to 13 years. This dynamometer provides a simple method to measure grip strength, and the results of this study provide further evidence of its performance in the measurement of grip strength.