LAUSR

STUDY DESIGN A controlled cross-sectional study. OBJECTIVE To compare the kinematics of lumbar axial rotation while sitting in an upright and forward bending position in men suffering with and without nonspecific chronic low back pain (NSCLBP). SUMMARY OF BACKGROUND DATA Lumbar rotation while sitting is an important factor in the mechanism of low back pain. Nevertheless, its kinematics has scarcely been investigated. METHODS Range of motion (ROM in), average velocity (AV), maximum velocity (MV) and maximal acceleration (MA) of lumbar rotation while sitting in an upright (UP-sitting) and full forward bending position (FFB-sitting) were examined using an industrial lumbar motion monitor in 50 men (25 with NSCLBP and 25 controls). Pain level and the Rolland Morris questionnaire (RMQ) were also included. RESULTS All examined kinematical parameters were significantly lower in men with NSCLBP compared with the controls (↓ROM = 16%-29%; ↓AV = 35%-53%; ↓MV = 3%-46%; ↓MA = 7%-44%) and significantly decreased when moving from UP-sitting to FFB-sitting. In the UP-sitting, the ROM and AV in both groups and the right rotation-MV in the NSCLBP group were always greater during the right rotation compared to the left (NSCLBP = ROM: Δ3.92°, AV: Δ2.74°, MV:Δ3.61°; controls = ROM: Δ3.46°, AV: Δ1.72°). The left rotation-MV was significantly greater compared to the right only in FFB-sitting in the controls (Δ3.03°). In all kinematical parameters in the NSCLBP group, no correlations were found in the VAS levels (4.43 ± 1.47) or RMQ total score (12.32 ± 5.44). CONCLUSIONS The kinematic parameters of lumbar rotation were reduced in men with NSCLBP compared with controls both in an UP-sitting and FFB-sitting. In both groups, NSCLBP and controls, asymmetry in lumbar rotation kinematics, was indicated as well as a decrease when moving from UP-sitting to FFB-sitting. LEVEL OF EVIDENCE 3.