Development of kinematics tests for the evaluation of lumbar proprioception and equilibration

Objective. This study aimed at developing lumbar repositioning and seated equilibration tests. Design. 3D-electrogoniometric study of trunk repositioning and equilibration in seated position. Background. Postural equilibrium and lumbar proprioception alterations have been shown in patients with low-back pain. Methods. In 21 healthy volunteers, pure flexion and flexion + rotation repositioning error was measured using 3D-electrogoniometry. Lumbar kinematics was analysed (time and frequency domain) during antero-posterior and lateral equilibration tests in seated position. Reproducibility and stability of the protocol were evaluated. Results. Reproducibility and stability were good. Pure flexion repositioning error was similar to previous reports. For flexion + rotation tests, repositioning error was 3° for flexion and 1° for rotation. Amplitude, imbalance time and power spectrum were significantly larger in lateral than in antero-posterior equilibration tests. Conclusions. The feasibility of kinematic analysis of lumbar repositioning and equilibration was shown. Repositioning error values were in agreement with previous studies. New tests and parameters were proposed. Lateral equilibration tests appeared more demanding than antero-posterior tests.