Ambulatory activity in youth with arthrogryposis: a cohort study.

BACKGROUND: Arthrogryposis is characterized by multiple congenital joint contractures that affect ambulation. This study compared ambulatory activity of subjects with the 2 most common forms of arthrogryposis and a control group of typically developing youth.

METHODS: This is a cross-sectional, cohort study. Thirteen ambulatory subjects with amyoplasia or distal arthrogryposis and 13 age- and sex-matched controls wore the StepWatch3 Activity Monitor on their ankles for 7 days. The daily frequency, duration, and intensity of ambulatory activity were measured. The parents of the subjects also completed Activities Scale for Kids, Performance-38 questionnaires to compare parent-reported activity levels with StepWatch3 Activity Monitor measurements.

RESULTS: The mean ages of the subject and control groups were 10.83 and 10.95 years, respectively, with 8 males and 5 females in each group. Subjects as compared with controls took significantly fewer steps, 5668+/-1134 versus 7685+/-1164, respectively (P=0.02) and spent significantly less of their active time at high step rates, 8% versus 13% (P=0.05). The average Activities Scale for Kids, Performance summary scores for subjects (76.8+/-18.9) were significantly lower than controls (90.6+/-7.2) (P=0.003).

CONCLUSIONS: We have been able to quantify the activity levels of children with amyoplasia and distal arthrogryposis relative to that of age- and sex-matched typically developing youth. Youth with arthrogryposis took significantly fewer steps, spent less time at high activity levels, and had significantly lower parental report of ambulatory and physical activity than controls.

LEVEL OF EVIDENCE: Cross-sectional comparison study, level II.