Reliability of potential clinical measures of muscle tone in the elbows of patients after stroke.

OBJECTIVES This study investigated the reliability of joint resting position (EJP), resistance to passive movement (ERM), and the angle of appearance of the resistance (EAR) as measures of muscle hypertonus of elbow flexors in patients after stroke. Previously, similar measures had been found reliable when applied to measuring shoulder and wrist hypertonus in patients after stroke. METHOD Forty-five subjects with stroke were randomly selected from occupational therapy admissions at two rehabilitation centers. Tone of elbow flexors was measured twice at the same sitting by two examiners. EJP and EAR were measured with a goniometer, and ERM was measured with a resistance rating scale. Correlations were calculated between first and second measurements by center and by high tone and poor upper extremity function subgroups (with correction for multiple correlations) to determine reliability. RESULTS Each of the three measures was highly reliable as demonstrated by a high correlation in at least one of the subgroups (Center 1: EJP, r = .964 for high tone subgroup; ERM, r = .789, EAR, r = .902, both in poor upper extremity function subgroup; and Center 2: EJP, r = .892, ERM, r = .938, both in poor upper extremity function subgroup; EAR, r = .666 for all subjects; all p values < .05). Correlations were especially high when data for subjects with high upper extremity function were eliminated. CONCLUSION Reliability of these three methods of measuring upper extremity muscle tone enhances their usefulness as well as therapists' confidence in their judicial application.