The Effect of Therapeutic Massage on H-Reflex Amplitude in Persons With a Spinal Cord Injury

Abstract

The effect of therapeutic massage on the H-reflex amplitude in persons without neurological impairment has been established. To investigate its effects in a sample of persons with a spinal cord injury (SCI), two independent but interrelated studies were undertaken. Study 1 investigated whether the recorded response (H-reflex amplitude) to massage with the subjects in the supine testing position was similar to that recorded in previous studies in which the subjects were tested in the prone position. This study was undertaken because the prone testing position was considered inappropriate for persons with SCI. In study 2, the therapeutic effect of massage (petrissage) on H-reflex amplitude in persons with SCI was examined. Seven persons without neurological impairment volunteered to participate in study 1, and 10 individuals with a traumatic SCI volunteered to participate in study 2. The two studies shared many methodological features and involved the recording of 10 H-reflex and M-response peak-to-peak amplitudes from the triceps surae muscle during each of five sequential, 3-minute time periods. Massage treatment (MASS) was given during the third time period, and the premassage time periods (C1, C2) and postmassage time periods (C3, C4) served as control conditions. Study 2, in addition to recording the peak-to-peak amplitudes of the recorded responses, also included the recording of the H-reflex latencies. The results of study 1 showed that massage applied with the subjects in the supine position decreased the H-reflex amplitude during the massage. A 56% decrease in the H-reflex amplitude was recorded. Study 2 demonstrated a 27% mean group decrease in the H-reflex peak-to-peak amplitude during the massage for all subjects, with variations in individual responses ranging from an increase in the H-reflex amplitude of 20% to a decrease of 84%. An analysis of variance revealed that the H-reflex means of the five conditions were significantly different. Newman-Keuls post hoc analyses revealed that the mean of the MASS condition (2.01 mV) was significantly different from the means of C1, C2, and C4 (2.79, 2.81, 2.58 mV). The mean of C3 (2.42 mV) was not found to be statistically different from the means of the other conditions. These changes were noted against a stable M-response. The results recorded in study 1 are comparable to those obtained with the subjects in the prone position. Based on these results, the supine position was adopted as the testing position for study 2. Study 2 further showed a decrease in H-reflex amplitude concomitant with massage in persons with SCI, but no long-term effects were noted.