Energy costs of manual therapy: effects of plinth height and an assistive device

The purpose of this investigation was to examine the metabolic and cardiopulmonary responses of an experienced therapist (8 years experience) performing manual therapy at standard (S) plinth height (31 in), elevated (E) plinth height (38 in), and standard (SMTH) and elevated (EMTH) plinth height wearing a manual therapy harness (MTH). The MTH, developed by one of the investigators (J.L.S.), is a vestlike device worn by the therapist, which, when attached to the patient, can be used to distract articular surfaces. The MTH allows the therapist more freedom of hand movement and use of body weight to help provide joint distraction. Inferior glide (Grade 3-Maitland) was provided to the lift hip of 12 individuals at a rate of 20 oscillations per minute for 4 minutes, continuously, so that steady-rate metabolic conditions could be established. Mean body mass and height for the 12 individuals was 70±10.5 kg and 174.5±13 cm, respectively. The therapist's heart rate returned to resting levels between each of the randomly assigned treatments. One subject was treated daily. The therapist (age 32) was chosen because of his clinical experience, similar height (172 em) and weight (73 kg) to the average adult American male, and excellent intra- and interday (5%≤ METs, 5%≤ HR) reproducibility. Metabolic equivalents (METs), heart rate (HR), and rate of perceived exertion (RPE) were measured and averaged for the last 2 minutes of each treatment condition. The therapist was unaware of day-to-day test results except for RPE. Mean METs were 3. 7,3.2,2.6, and 2.4 for S, E, SMTH, and EMTH, respectively. Mean HRs were .117, 110, 104, and 93 beats/min for S, E, SMTH, and EMTH, respectively. RPE was 11. 0,8.7, 7.9, and 7.3jorS, E, SMTH, and EMTH, respectively. Repeated-measures analysis of variance (Scheffé F-test) revealed that SMTH and EMTH METs were similar, and significantly different (p≤0.05) from Sand E. METs for E were significantly different and lower than for S. HRs were significantly greater during E than the SMTH condition. RPE for S was significantly greater than SMTH, E, or EMTH. It can be concluded that the MTH significantly reduced the physiologic cost of providing manual therapy at either standard or elevated plinth height. further studies on these types of assistive devices and the effects of health status of the therapist on the provision of manual therapy treatments at various plinth heights are needed.