Aims: Recurrence rate of low back pain is high because of the deþciency of Ôpostural and movement controlñ. The aim was to develop a clinically useful, valid and reproducible measure for postural control in a seated position. Accuracy to control equilibrium was measured in LBP patients. Methods: Postural control was investigated in 19 chronic aspeciþc LBP patients (20– 55years, mean 42,3y) and 20 healthy controls (20–55years, mean 37,8y). An unstable seated position was created by sitting on a balance board with a swing angle of 28¡. The chair and one foot were placed on the force platform of a Balance Master¨, testing four difþculty levels using arm movements and occlusion of vision. Outcome was measured using force plate data and visual observations. Results: A high test-retest reproducibility was measured for the low back pain patients (87.5%) but not for the healthy controls (32.5%). Discriminant analysis of all variables divided the total group (n=39) with an accuracy 97.4% in the LBP group (n=19) and the controls (n=20). Patients show increased difþculty to maintain seated balance. Conclusions: Chronic LBPP could be recognized as having signiþcantly more difþculty to maintain control of seated balance These þndings were conþrmed during observation using a 5 point scale. Pro-prioception impairment in LBP patients can be documented in clinical practice through difþculty in sitting on a balance board.

Aims: To evaluate the inßuence of wobble board training on complaints and on the control of ankle motion in functionally unstable ankles during a sudden inversion in the standing position. Methods: 25 patients were randomly allocated to a training group (13 persons, 15 ankles), or to a control group (12 persons, 15 ankles). Patients were only included if they suffered invalidating disabilities following at least two ankle inversion trau-mañs followed by at least 6 weeks of rehabilitation. They were randomly allocated to a wobble board training group (6 weeks), or to a no intervention control group. Accelerometric and electromyographic analysis of functional control during a sudden ankle inversion of 50û in the standing position and a validated functional impairments index were used to assess efþcacy. Results: Trained patients with Òmedium latencyÒ reßexes (n= 5) showed signiþcantly earlier decelerations with the ankle displaying in a signiþcantly smaller inversion displacement (p< 0.05, power=0.96). Trained patients with Òshort latencyÒ reßexes (n= 10) showed no signiþcant change in inversion control. All trained patients showed signiþ cantly less impairments compared to the control group. Conclusions: These results support the treatment strategy that wobble board training should be included in the rehabilitation of functional ankle instability.