Musculoskeletal findings and disability in alkaptonuria.

OBJECTIVE: To describe the musculoskeletal (MSK) findings in patients with alkaptonuria and to show which of these factors are associated with disability in this population. METHODS: This is a prospective cross-sectional MSK assessment of subjects. Participants included 53 patients with alkaptonuria across the life span, 22 female and 31 male, mean age 43.6 years (10-80 yrs), participating in a natural history study supported by the National Human Genome Research Institute (NHGRI). Assessments included objective measures of the MSK system (range of motion, radiographic assessment of joints and spine, etc.) and questionnaires including the Human Activity Profile (HAP), Health Assessment Questionnaire (HAQ), SF-36 health survey, and the Fatigue Assessment Instrument. RESULTS: There were 18 patients with kyphosis, 16 with scoliosis, 16 with marked reduction in range of motion of at least one major joint, 15 with joint replacements of major joints, 11 with tendon ruptures. A positive Schober's test was highly correlated with substantial functional loss and associated with disability as measured by the HAP (p < or = 0.0001), HAQ (p < or = 0.0001), and the physical component summary (p < or = 0.0001) of the SF-36 health survey. Severity of lumbar spine involvement had the greatest correlation with disability measures (p < or = 0.0001). All objective and subjective physical measures worsened with age. CONCLUSION: Disability is common and severe in patients with alkaptonuria and correlates well with physical findings. Disability does not correlate with self-reports of mental competencies. Aging with alkaptonuria is associated with progressive disability.

Brief assessment of motor function: reliability and concurrent validity of the Gross Motor Scale.

OBJECTIVE: The Brief Assessment of Motor Function (BAMF) is a series of 10-point ordinal scales developed for rapid description of gross motor, fine motor, and oral motor performance. We examined interrater and intrarater reliability and concurrent validity of the BAMF Gross Motor Scale. DESIGN: This validation study included 48 children (age, 5 mo to 17 yr) with a wide range of gross motor capability. Ten children with varied diagnoses participated in the reliability study. For concurrent validity, the BAMF performance of 38 children with osteogenesis imperfecta was compared with scores on the Peabody Developmental Motor Scales, laboratory gait analysis, and manual muscle testing. RESULTS: Reliability values for intraclass correlations were 0.996 (interrater) and 1.00 (intrarater). Significant relationships were identified between the BAMF and gait speed ( r = 0.68, P < 0.0001), stride length (r = 0.71, P < 0.0001), duration of double-limb support ( r = -0.40, P < 0.03), number of weak muscles (r = -0.74, P< 0.0001), and the Peabody Developmental Motor Scales (r = 0.95, P < 0.0001). Number of weak muscles was the strongest predictor of BAMF score R2 = 0.5080, F = 24.77, P < 0.0001). CONCLUSIONS: The BAMF demonstrates good reliability for children with a range of diagnoses and acceptable concurrent validity with gross motor development, muscle strength, and formal gait assessment in children with osteogenesis imperfecta.