Comparing postural strategy changes following adapted versus non-adapted responses in subjects with and without spinal stenosis.

Musculoskeletal evaluation skills are needed to examine postural compensation techniques, but little is known about ground reaction forces (GRF) in standing posture. Even though a number of studies have evaluated GRF in patients with low back pain (LBP) during vertical perturbations, it would be important to consider compensation characteristics which might be associated with abnormal patterns of postural responses. The vertical excursions of the body center of mass (BCOM) were measured with delay time and normalized amplitude of GRF. Overall, there was no difference based on the vertical excursion of the BCOM (F=0.12, p=0.90), amplitude of the normalized GRF (F=0.16, p=0.74), or response time (F=1.98, p=0.17) between subjects with and without spinal stenosis. There was a gender difference based on the vertical excursion of the normalized BCOM (F=5.92, p=0.02) as well as the normalized amplitude of GRF (F=4.17, p=0.04). It was shown that male subjects implemented better adjustment strategies during adapted and non-adapted responses in order to improve body stability. In this way, manual therapists should be aware that gender differences exist in patients with spinal stenosis since the condition may change the individual's postural adjustment ability.