Achilles and patellar tendinopathy are overuse injuries characterized by localized tendon pain with loading that are common among athletes, but, may also be experienced by sedentary individuals.

Isolated eccentric muscle loading has been the intervention of choice for conservative management of these conditions. However, other muscle loading programs such as eccentric-concentric progressing to eccentric and eccentric-concentric isotonic (heavy-slow resistance, HSR) have been proposed interventions for conservative management as well. This systematic review synthesized evidence from studies comparing two or more loading programs in Achilles and patellar tendinopathy rehabilitation and investigated non-clinical outcomes, such as improved imaging, associated with clinical outcomes. This review found equivalent evidence for eccentric-concentric progressing to eccentric loading and greater evidence for HSR loading as compared to isolated eccentric loading for Achilles and patellar tendinopathy, respectively. This review also identified that improved neuromuscular performance, such as torque and endurance, is consistently associated with improved clinical outcomes in both Achilles and patellar tendinopathy whereas improved jump performance is associated with Achilles but not patellar tendon clinical outcomes.

Improved imaging was found to be associated with patellar (HSR only) but not Achilles tendon clinical outcomes. The authors suggest the equivalency is due to similar load intensity between isolated eccentric muscle loading and eccentric-concentric progressing to eccentric muscle loading. In asymptomatic participants, load intensity can be maximized by using isolated eccentric loading only. However, in patients with tendinopathy, load-intensity may not be maximized due to symptom irritability. The authors also suggest that improved outcomes with HSR loading in the patellar tendon may be due to longer duration heavier contractions that increase the strain stimulus for tendon adaptation. However, the authors highlighted the fact that HSR loading has only been investigated in two studies, both in the patellar tendon.

The findings of this review, despite being somewhat limited due to a scarcity of high quality primary studies, suggest improvement in Achilles and patellar tendinopathy is not dependent upon isolated eccentric loading. While the included studies do not specifically describe the methods utilized to determine the appropriate exercise load, these findings are broadly in alignment with MDT principles in treatment of contractile dysfuction: progressive loading, culminating in maximum or near-maximum stresses for tissues that require heavy load-bearing for normal function. The precise exercise prescription may not be as important as achieving the appropriate load.

Extremities: Systematic reviews