Intra-rater reliability, standard error of measurement, and minimal detectable change of two muscle compressibility measurement methods using ultrasonography in spastic hand flexor muscles.

PURPOSE: Calculate the intra-rater reliability of measuring muscle compressibility for spastic hand flexors using ultrasonography in two different methods among post-stroke patients.

METHODS AND MATERIALS: Twenty-four patients with a mean age of 54.50 ± 9.44 participated in this study. Muscle compressibility was measured using two methods in the middle of forearm at the ulnar side: longitudinal and transverse scanning. All measurements were conducted over 2 days with a 24-h interval. Standard error of measurement (SEM) and minimal detectable change (MDC) were also calculated.

RESULTS

The analysis showed that measuring muscle compressibility through longitudinal scanning had excellent reliability (0.902) falling within the good to excellent range (0.789-0.956) and the reliability of transverse scanning was considered good (0.846) with a range from moderate to excellent (0.679-0.930). The SEM and MDC values were 1.55 and 4.28 for longitudinal scanning and 2.27 and 6.27 for transverse scanning methods, respectively.

CONCLUSION

The measurement of muscle compressibility in the spastic hand flexor muscles of post-stroke patients is a reliable assessment method, whether longitudinal or transverse. However, the lower values of SEM and MDC for the longitudinal scanning method show that this method may be more sensitive to changes than the transverse scanning method and has a greater precision in measurement.Implications for RehabilitationCompressibility is a relatively new parameter in diagnostic musculoskeletal ultrasonography that is calculated from muscle thickness measurements to evaluate muscle elasticity.The compressibility parameter can be used to evaluate treatment methods that claim to reduce or manage muscle spasticity.The lower values of standard error of measurement and minimal detectable change for the longitudinal scanning method show that this method may be more sensitive to changes than the transverse scanning method and has a greater precision in measurement.