Spinal range of motion during different swim strokes in people with chronic low back pain: a randomised crossover trial.

BACKGROUND

The spinal biomechanics of different swim strokes may impact swimming's suitability for chronic low back pain patients, but this remains unexplored.

OBJECTIVE

Compare spinal range of motion between different swimming strokes in chronic low back pain patients.

DESIGN

Randomised crossover trial.

METHOD: Chronic low back pain participants completed 100m of freestyle, breaststroke, and backstroke in a random order during one indoor pool session. Inertial measurement units were worn at T2 and S2 spinal landmarks. The primary outcome was inter-sensor range of motion (T2 and S2 sensor difference) for flexion/extension, rotation and lateral flexion. Mixed-effect models compared strokes.

RESULTS

Twenty-two females and 8 males participated (age: 43 ± 15, pain intensity: 2.9 ± 2.2). Flexion/extension range of motion was greatest for breaststroke (22.6 ± 11.3°); increases were small compared to freestyle (Mean difference [MD]: 3.6 [95 % Confidence interval: -2.1 to 9.2]; p = 0.29) and large compared to backstroke (MD: 8.8 [3.2 to 14.5]; p = 0.001). Rotation range of motion was greatest for freestyle (36.7 ± 23.3°); increases were trivial compared to backstroke (MD: 2.6 [-6.5 to 11.6]; p = 0.78) and large compared to breaststroke (MD: 27.1 [18.1 to 36.1]; p < 0.001). Lateral flexion range of motion was greatest for freestyle (32.6 ± 10.6°); increases were moderate to large compared to backstroke (MD: 6.7 [1.2 to 12.2]; p = 0.01) and breaststroke (MD: 25.2 [19.7 to 30.7]; p < 0.001).

CONCLUSION

Freestyle produced the largest overall spinal range of motion, with the most rotation and lateral flexion. Breaststroke produced the most flexion/extension. Backstroke produced mostly rotation and lateral flexion.