Introduction:
The study concerns patients with lumbar spine pain syndrome who had undergone therapy by the McKenzie method.

The primary aim of the study was verification of the correlation between restoration of mobility and pain reduction, and physical activity of patients.

Material and methods:
The study was conducted by the McKenzie method of mechanical diagnosis and therapy (MDT), and included patients with lumbar spine pain syndrome without radiation to the lower limbs. The patients were purposefully qualified to the appropriate group of spine pain syndrome and, subsequently, their physical performance and exercise capacity were assessed.

Results:
Progress in treatment was manifested by the reduction of pain and restoration of spinal mobility in the sagittal plane. The study confirmed evident diagnostic and therapeutic advantages of the McKenzie method.

Conclusions:
During the therapeutic process, the patients’ physical activity and lumbar spine pain was successfully maintained on an optimum level. It may be presumed that physical activity exerts a beneficial effect on the progression in the improvement of spine mobility at the subsequent stages of therapy using the McKenzie method. Patients who were more active showed greater spine mobility than those insufficiently active. The study indicated a significant correlation between physical activity and the improvement in spine mobility. Also, more active patients demonstrated faster reduction or elimination of pain.