Clinically Relevant Decreases in Neck/Shoulder Pain Among Office Workers Are Associated With Strength Training Adherence and Exercise Compliance: Explorative Analyses From a Randomized Controlled Trial.

Objective: The objectives of this study were to quantify training adherence and exercise compliance during a workplace-based strength training intervention delivered to office workers over a 12-week period and to analyze the association with clinically relevant pain reductions.

Methods: A subsample of 269 participants completed a training diary from which measures of training adherence and exercise compliance (training volume, load, and progression) were calculated. The intervention consisted of 5 specific exercises targeting the neck/shoulder area (neck, shoulders, and upper back). The associations of training adherence, quitting time, and measures of exercise compliance with 3-month pain intensity (on a scale from 0 to 9) were analyzed for the whole sample, pain cases (reporting pain of ≥3 at baseline), participants attaining/not attaining clinically relevant pain reductions (≥30%), and participants meeting/not meeting per-protocol training adherence of ≥70%.

Results: Participants reported reduced pain in the neck/shoulder area after 12 weeks of specific strength training, especially women and pain cases, with the caveat that attaining clinically relevant pain reductions depended on the levels of training adherence and exercise compliance attained. Over the 12-week intervention, 30% of the participants were absent for a minimum of 2 consecutive weeks (quitting time), with the median quitting time at approximately weeks 6 to 8. With a threshold of 70% training adherence, a total training volume of approximately 11,000 kg (only in women) and progressions of 1 to 2 times baseline values were shown to be significant for clinically relevant pain reductions.

Conclusion: Strength training produced clinically relevant reductions in neck/shoulder pain when appropriate levels of training adherence and exercise compliance were attained. This finding was particularly evident for women and pain cases. We advocate for the inclusion of both training adherence and exercise compliance measures in future studies. To optimize intervention benefits, motivational activities after 6 weeks are needed to avoid participants quitting.

Impact: These data can be used to design and prescribe clinically relevant rehabilitation pain programs and interventions.