Manual application of controlled forces to thoracic and lumbar spine with a device: rated comfort for the receiver's back and the applier's hands.
OBJECTIVE
High volumes of manual therapy work can lead to overuse hand and wrist injuries. This study evaluated hand and back comfort in asymptomatic volunteers during spinal mobilization carried out with an instrumented manual therapy tool.


METHODS
This crossover design study examined 36 asymptomatic physiotherapy students that were tested in pairs. One participant assumed the role of the simulated therapist and the other the simulated patient, before reversing roles. Posteroanterior mobilization conditions formed by using 2 spinal segments (thoracic/lumbar), 2 force application methods (hands/device), and 3 grades of mobilization were applied in a random order. After each combination, both participants in each pair rated hand or back comfort, respectively, on a 100-mm visual analogue scale. Data were analyzed by analysis of variance.


RESULTS
Rated back comfort was greater for hands than for the device and decreased with greater applied force. When the original hard rubber device tip was changed to one of soft molded rubber, both back and hand comfort improved significantly. Although tool mobilization was still rated as significantly less comfortable than mobilization with hands only, this difference was approximately half the discomfort experienced as the grade of mobilization increased from grade I to grade III. For hand comfort when using the softer device tip, the method of force application was no longer a significant determinant of comfort.


CONCLUSIONS
The mobilizing tool with a molded rubber tip was acceptably comfortable in use with asymptomatic backs and hands. Further research is indicated in manual therapy settings with therapists who have experienced hand pain.
Waddington
Gordon
G
School of Health Sciences, University of Canberra, Canberra, Australia. gordon.waddington@canberra.edu.au
Lau
Gordon
G
Adams
Roger
R
D000328:Adult; D018592:Cross-Over Studies; D012090:Cumulative Trauma Disorders / Q000517:prevention & control; D004867:Equipment Design; D006804:Ergonomics; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D020393:Manipulation, Spinal / Q000295:instrumentation*; D009784:Occupational Diseases / Q000517:prevention & control; D010147:Pain Measurement; D013904:Thoracic Vertebrae / Q000502:physiology*