This study compared the effect of manipulation with a period of normal activity on the range of intervertebral sidebending.

Thirty asymptomatic male volunteers were randomised to treatment or control groups. All were subjected to low-dose X-ray screening through 80° of passive lumbar spine side-bending. Motion sequences were digitised at a 5Hz sampling rate. The treatment group (n=16) had rotary manipulation to each lumbar linkage, followed by normal activity. The control group (n=14) had normal activity only. Both groups were then re-screened. Each vertebral pair was tracked and intervertebral rotation throughout the motion measured. Three subjects were analysed 10 times for reliability and all intervertebral motion was tracked twice.

Twenty-one manipulated linkages and 10 controls met the reliability criteria. For non-manipulated segments the mean range at first screening was 14.2° (SD 1.39) and manipulated segments 12.8° (SD 3.81). The range of the non-manipulated segments increased by +0.9o and the manipulated segments by +0.4°.

The change in manipulated segments was negligible and similar to controls, although the instrument can be sufficiently reliable to measure a 2° difference. The technique is sufficiently robust to determine if spinal manipulation changes these ranges in selected patients.