Impact of a high intensity training program on changes in activity level of persons with chronic nonspecific low back pain: data of a clinical pilot trial

Abstract

Introduction Exercise therapy is effective in the treatment of persons with chronic nonspecific low back pain (CNSLBP)1. However, there is little consensus concerning the optimal training intensity that may lead to training effects. High intensity training (HIT) has shown promising effects in other populations. Improvements such as a reduction of pain or progression in functional ability may change the level of actual performance in CNSLBP. Because previous research has shown that persons with CNSLBP have difficulties with objectively reporting their amount of daily activity2, and the use of one accelerometer for monitoring changes in activity level is questionable, a combination of accelerometers is used to provide objective assessment of activity level.

Purpose/Aim The aim of this study is to assess to which extent a HIT program may improve the actual performance at the ICF activity level of persons with CNSLBP.

Materials and Methods A clinical pilot trial involving 20 persons with CNSLBP was conducted. Participants followed a six week training program (2x/week, 2 hours) that consisted of either a high intensity training program (strength and endurance), or a regular care program. The actual amount of arm-hand use (i.e. time and intensity) in combination with and without hip movement during daily activities was assessed at baseline and after six weeks of training. Assessment consisted of the continuous recording of movement of both arms (left wrist, right wrist) and the torso (hip) over three consecutive days, using three accelerometers (Actigraph GT3X). A repeated measures design, involving pre- and post-intervention measurements was used.

Results Data usable for analysis were obtained from eight persons in the regular care group (median age=43,40 years) and ten persons in the HIT group (median age=38.50 years). Results of actual activity show no significant changes within both groups (pre-post) or between the groups, neither in “time and intensity of arm-hand use while the hip is not moving”, nor in “time and intensity of bilateral or unilateral arm movement with concurrent movement at the hip (i.e. gait, stairs, etc.)”.

Discussion Results of this study corroborate the findings of previous studies that no differences in activity levels are found after rehabilitation in low back pain patients. However, uncertainty remains whether this is due to a lack of sensitivity of the measurement or may be caused by actual characteristics of the disorder.

Conclusion(s) Data from a combination of three accelerometers do not show changes in activity levels in persons with CNSLBP who follow a six week HIT program or regular care. However, more data should be gathered to further elucidate any potential differences between HIT and conventional therapy approaches in CNSLPB patients.