S.P.15 Utility of subjective pain scales for assessments of standing with knee–ankle–foot-orthoses in Duchenne muscular dystrophy

Abstract

Standing with knee–ankle–foot orthoses (KAFOs) in rehabilitation for Duchenne muscular dystrophy (DMD) helps prevent lower limb contracture and progression of scoliosis. As joint contracture progresses, compression from orthoses can cause pain, making it difficult to continue standing. The purpose of this study was to evaluate the utility of subjective pain scales in assessments of continued standing with KAFOs. Subjects were 69 boys with DMD. The following were assessed 30 minutes after standing with KAFOs: visual analogue scale (VAS), Wong–Baker face scale (WBFS), and Lorish–Maisiak face scale (LMFS). Joint contracture was evaluated during hip extension, knee extension, and ankle dorsiflexion by measuring range of motion (ROM) with a goniometer. Spearman’s correlation coefficients were used to assess the relationship between pain scales and ROM. Receiver operating characteristic (ROC) curve analysis was used to calculate the sensitivity and specificity of each pain scale during continued standing with KAFOs. Factors associated with continued standing with KAFOs were determined using the cut-off values for each scale. ROM for ankle dorsiflexion was moderately correlated with VAS (ρ = −0.42, p < 0.001), WBFS (ρ = −0.37, p = 0.004), and LMFS (ρ = −0.34, p = 0.004). ROM for knee extension was moderately correlated with WBFS (ρ = −0.30, p = 0.027), and weakly correlated with LMFS (ρ = −0.28, p = 0.041). There was no correlation between knee extension and VAS (ρ = −0.25, p = 0.072). ROM of hip extension was moderately correlated with WBFS (ρ = −0.32, p = 0.024) and LMFS (ρ = −0.36, p = 0.011), and weakly correlated with VAS (ρ = −0.297, p = 0.036). The optimal cut-off values for continued standing with KAFOs were 80 mm (100%) for VAS, 4 (100%) for WBFS, and 17 (100%) for LMFS. Our findings revealed correlations between pain and joint contracture, suggesting that these subjective pain scales are useful for assessments of continued standing with KAFOs.