The effect of low back pain on spine kinematics: A systematic review and meta-analysis.

BACKGROUND: Although impairments in dorso-lumbar spine mobility have been previously reported in patients with low back pain, its exact mechanism is not yet clear. Therefore, the purpose of this systematic review and meta-analysis is to investigate and compare spinal kinematics between subjects with and without low back pain and identify appropriate tools to evaluate it. METHODS: The PubMed, Scopus and Web of Science databases were searched for relevant literature. The search strategy was mainly focused on studies investigating lumbar kinematics in subjects with and without low back pain during clinical functional tests, gait, sports and daily functional activities. Papers were selected if at least one of these outputs was reported: lumbar range of motion, lumbar velocity, lumbar acceleration and deceleration, lordosis angle or lumbar excursion. FINDINGS: Among 804 papers, 48 met the review eligibility criteria and 29 were eligible to perform a meta-analysis. Lumbar range of motion was the primary outcome measured. A statistically significant limitation of the lumbar mobility was found in low back pain group in all planes, and in the frontal and transverse planes for thoracic range of motion, but there is no significant limitation for pelvic mobility. The amount of limitation was found to be more important in the lumbar sagittal plane and during challenging functional activities in comparison with simple activities. INTERPRETATION: The findings of this review provide insight into the impact of low back pain on spinal kinematics during specific movements, contributing to our understanding of this relationship and suggesting potential clinical implications.

Biomechanics of the intra-operative lateral decubitus position for the scoliotic spine: effect of the pelvic obliquity.

The intra-operative prone position used for the posterior instrumentation of scoliotic patients has been shown to reduce the spinal deformities prior to instrumentation by 37% on average. However, the effects of the lateral decubitus position used for anterior approaches and minimally invasive techniques have not been investigated. The objectives were to characterize, model and study the biomechanics of this intra-operative posture. Several clinical indices were measured on the pre- and intra-operative radiographs of six scoliotic patients. A personalized finite element mode (FEM) was developed using the pre-op 3D reconstruction, and a three-step method was developed to simulate the lateral decubitus positioning. Two additional intra-op postures, simulating different pelvic obliquities, were also tested by varying the inclination of L5. The radiographic evaluation of the lateral decubitus position showed a significant reduction of 44% of the major curve with 18 mm of apical vertebra translation. The FEM was able to reproduce the intra-op spine geometry with no significant difference with the measured values. Simulations also showed that the pelvic obliquity had different effects on the lumbar and major Cobb angles depending on the scoliotic curve type. The lateral decubitus posture reduces significantly the scoliotic curvatures prior to instrumentation, which was dependent on the pelvic obliquity.

A comparison of clutching movements of freely adjusted and imposed pedal configurations for identifying discomfort assessment criteria.

This paper focuses on the effects of the free pedal position adjustment on clutching movements of the left lower limb as well as on the perceived discomfort. Six automotive clutch pedal configurations were tested by 20 subjects (5 young females, 5 young males, 5 older females, 5 older males) using a multi-adjustable experimental mock-up. Results showed that the pedal position was adjusted to ensure a good starting pedal position allowing a less flexed ankle and avoiding unnecessary leg displacement from the foot rest to the position at start depression. Pedal position adjustment seemed not motivated by reducing joint torque though discomfort ratings were found significantly correlated with knee and ankle torques at the end of depression. The present work also illustrates that the less-constrained motion concept is helpful for a better understanding of people preference and useful for identifying motion-related biomechanical parameters to be considered for defining assessment criteria.