Postural sensorimotor training versus sham exercise in physiotherapy of patients with chronic non-specific low back pain: An exploratory randomised controlled trial

<div><p>Sensorimotor training (SMT) is popularly applied as exercise in rehabilitation settings, particularly for musculoskeletal pain. With insufficient evidence on its effect on pain and function, this exploratory randomised controlled trial investigated the potential effects of SMT in rehabilitation of chronic non-specific low back pain. Two arms received 9x30 minutes physiotherapy with added interventions: The experimental arm received 15 minutes of postural SMT while the comparator arm performed 15 minutes of added sub-effective low-intensity training. A treatment blinded tester assessed outcomes at baseline 2–4 days prior to intervention, pre- and post-intervention, and at 4-week follow-up. Main outcomes were pain and functional status assessed with a 0–100mm visual analogue scale and the Oswestry Disability Questionnaire. Additionally, postural control was analysed using a video-based tracking system and a pressure plate during perturbed stance. Robust, nonparametric multivariate hypothesis testing was performed. 22 patients (11 females, aged 32 to 75 years) with mild to moderate chronic pain and functional limitations were included for analysis (11 per arm). At post-intervention, average values of primary outcomes improved slightly, but not to a clinically relevant or statistically significant extent. At 4-week follow-up, there was a significant improvement by 12 percentage points (pp) on the functional status questionnaire in the SMT-group (95% confidence intervall (CI) = 5.3pp to 17.7pp, <i>p</i> < 0.001) but not in the control group (4 pp improvement, CI = 11.8pp to 19.2pp). However, group-by-time interaction effects for functional status (Q = 3.3, 19 p = 0.07) and pain (Q = 0.84, p = 0.51) were non-significant. Secondary kinematic outcomes did not change over time in either of the groups. Despite significant improvement of functional status after SMT, overall findings of this exploratory study suggest that SMT provides no added benefit for pain reduction or functional improvement in patients with moderate chronic non-specific low back pain.</p><p><b><i>Trial registration</i></b>: ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02304120" target="_blank">NCT02304120</a> and related study protocol, DOI: <a href="https://doi.org/10.1186/1471-2474-15-382" target="_blank">10.1186/1471-2474-15-382</a>.</p></div

Schematic representation of the defined segment angles.

<p>Θ_<i>N</i> = Neck angle; Θ_<i>L</i> = Lumbar angle; Θ_<i>H</i> = Hip angle; Θ_<i>K</i> = Knee angle; Θ_<i>A</i> = Ankle angle; Θ_<i>F</i> = Foot angle; Marker positions (from head to toe): corner of the eye (orbital process of the zygomatic bone), acromion, anterior superior iliac spine, greater trochanter, lateral condyle of femur, lateral malleolus, 1st metatarsal bone.</p

Study flow chart.

<p>BL = baseline assessment; <i>T</i>₀ = pre-test, <i>T</i>₁ = post-test, <i>T</i>₂ = 4-week follow-up. SMT = sensorimotor training group; SLT = sub-effective low-intensity endurance training group; PT = standard physiotherapy.</p

Principal component analysis of the involved segments.

<p>Principal component analysis of the involved segments.</p

Mean, standard deviation and range values for characteristics of the study population.

<p>Mean, standard deviation and range values for characteristics of the study population.</p

Main results of primary and secondary outcomes at 4 measurement events.

<p>Main results of primary and secondary outcomes at 4 measurement events.</p

Group comparison of variance components.

<p>Across trials mean variance components during the first second of the active response phase after platform release. CG = control group; CNLBP = Chronic non-specific low back pain group.</p

Mean and range values for characteristics of the study population.

<p>Mean and range values for characteristics of the study population.</p

Illustration of the measurement setup.

<p>Illustration of the measurement setup.</p

Group comparison of segmental angle excursions.

<p>Distribution of the angle excursions of the investigated segments with highest PCA loading. Across trial average values computed for the first second of the active response phase. *<i>P</i> < .025; **<i>P</i> < .001.</p