Fulvio Dal Farra (Dept. of Information Engineering, University of Brescia, Brescia, Italy)
Nicola Francesco Lopomo (Dept. of Design, Politecnico of Milan, Milano Italy)
Matteo Fascia (Dept. of Information Engineering, University of Brescia, Brescia, Italy)
Emilia Scalona (Dept. of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy)
Veronica Cimolin (Dept. of Electronics, Information and Bioengineering, Politecnico of Milan, Milano, Italy
Non-specific low back pain (NS-LBP) is a frequent musculoskeletal condition affecting up to 80% of the population in their lifetime. Perturbations in spinal and lower limb dynamics have been considered as potential factors directly involved in NS-LBP, including joint rigidity, muscle weakness and poor neuromuscular function. All these factors could lead to asymmetrical or abnormal mechanical loading of the lumbar spine.
Since walking represents one of the activities that is routinely repeated throughout the whole day, it can be affected and contribute to pain, activity limitations, and disability in subjects presenting NS-LBP. Despite the large number of studies carried out over the years, to the best of our knowledge, no systematic review exists on this topic.
Therefore, we carried out a systematic review focused to provide a structured synthesis of the actual evidence on this topic, specifically addressing the use of quantitative and instrumental assessing methods.
The conceptualization of this review followed the “2020 Preferred Reporting Items for Systematic Reviews and Meta-Analysis” (PRISMA 2020 checklist) and the protocol was preliminary registered in PROSPERO (ID: CRD42023431380). A search strategy was implemented in Medline, Embase, Scopus, Web of Science, and IEEE Xplore databases, up to March 2024.
Inclusion criteria were: any analytical observational research instrumentally assessing the trunk and lower limbs kinematics of spontaneous walking in NS-LBP, in a comparison with healthy people. As for the exclusion criteria, studies where walking was assessed on the treadmill, or studies dealing with subjects affected by other conditions affecting the walking performance were excluded.
Study selection and data extraction were performed by two blinded reviewers, the methodological quality was evaluated by the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Analytical Cross-Sectional Studies, and the quality of the evidence was rated through GRADE framework.
Overall, a total of 19 cross-sectional studies were included in this review and none of those was found without any methodological issues. A meta-analysis was only possible for some of the examined spatial-temporal parameters, all the outcomes related to joint motion were summarized through a qualitative synthesis.
The meta-analysis showed a lower gait velocity [-15.42 (-22.78, -8.06) cm/s; p≤ 0.0001], a lower cadence [-9.85 (-18.72, -0.99) steps/min; p= 0.03] and a lower step length [-6.30 (-11.83; -0.77) cm; p= 0.03] in NS-LBP compared to healthy people. Regarding motion analysis, a few authors observed a less and asymmetrical motion of the lower spine in the frontal and in the transverse plane. Changes in lower limbs kinematics were reported sporadically and resulted inconsistent. The quality of the evidence was rated as very-low due to the presence of study design issues, inconsistency, indirectness and imprecision.
There is very-low quality evidence that gait speed, cadence and step length are reduced in patients with NS-LBP, and that stride length does not differ compared to healthy people. There is proof of a movement reduction in the lower lumbar spine and in the pelvis, both in the transverse and in the frontal plane. No differences in the lower limb kinematics appeared to be consistent over the studies. The importance of instrumental motion assessment in NS-LBP should be well taken into consideration by the healthcare policies, so that the applicability of such procedures may be guaranteed.
High-quality observational studies are needed to improve the quality of the evidence and to determine if the kinematic modifications in NS-LBP people are related to physical or psycho-behavioral factors, and if they are caused by the presence of pain or by physical re-adaptations.
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