Objective: To compare the effectiveness of different energy densities of extracorporeal shock wave therapy (ESWT) for managing chronic heel pain.
Design: A randomized clinical trial.
Setting: Hospital-based practice.
Subjects: Fifty-seven patients with chronic heel pain were recruited; eight patients withdrew from the study.
Interventions: Subjects were randomized into three groups receiving: (1) a 'fixed' energy density, (2) 'maximum tolerable' energy density, or (3) control treatment once a week for three weeks.
Outcome measures: Pain on palpation, pain on tension, maximum tolerable walking/standing duration and Foot Function Index were assessed before treatment in each treatment session and at the three-week follow-up.
Results: By week 3, the 'maximum tolerable' energy density group experienced a 66% cumulative reduction in pain from tension, a 65% reduction on palpation and a 112% cumulative increase in maximum tolerable walking/standing duration. The 'fixed' energy density group experienced a 45% cumulative reduction in pain from tension, a 32% reduction in pain on palpation, and a 45% increase in walking/standing tolerance. The 'maximum tolerable' energy density group also showed a significantly greater reduction in Foot Function Index scores than the other two groups. Therapeutic effects were maintained at least up to the three-week follow-up period. The control group had no significant changes in any outcome measures across time periods.
Conclusion: The delivery of ESWT with a maximum tolerable energy density is a more effective treatment protocol than a fixed energy density in terms of relieving pain and restoring the functional activity of people suffering from chronic heel pain. The analgesic effects were maintained at least up to the three-week follow-up.