The Effects of Conventional Physical Therapy and Eccentric Strengthening for Insertional Achilles Tendinopathy

SLR - November 2014 - Keith Grimes

Reference: Kedia M, Williams M, Jain L, Barron M, Bird N, Blackwell B, Richardson D, Ishikawa S, Murphy GA. The Effects of Conventional Physical Therapy and Eccentric Strengthening for Insertional Achilles Tendinopathy. The International Journal of Sports Physical Therapy. 2014; 9: 488-497.

Scientific Literature Review

Reviewed By: Keith Grimes, DPM
Residency Program: Albert Einstein Medical Center

Podiatric Relevance: Insertional Achilles tendinopathy is a common overuse injury that is frequently seen in podiatric practices. This condition is most commonly associated with middle-aged, recreational athletes, but it is also often observed in patients of both sexes and with varying activity levels. Current conservative standards of care include activity modification, cryotherapy, ultrasound, stretching, orthotics, heel lifts, night splints, NSAIDs, and physical therapy.  Recent literature has suggested that eccentric strengthening exercises are an effective modality in the treatment of mid-portion Achilles tendinopathy, but less is known regarding its effectiveness in the treatment of insertional Achilles tendinopathy. The primary purpose of this study was to evaluate the effect that eccentric training had on pain and function in a small group of patients with insertional Achilles tendinopathy. This study also sought to determine in BMI, activity level, and baseline range of motion and strength had any effect on treatment outcomes.

Methods: The authors present a prospective, single-blind, randomized study that took place at four separate clinic locations between February 2007 and October 2010. Participants in this study were selected from a population of patients diagnosed with insertional Achilles tendinopathy, who were referred by orthopaedic foot and ankle surgeons for conventional physical therapy treatment.  Inclusion criteria for this study were symptoms being present for at least three months and the patient being over 18 years old. Patients were excluded from the study if they had rheumatoid arthritis, generalized polyarthritis, severe endocrine disease, Reiter syndrome, advanced peripheral vascular disease, local infection, tumor, bleeding disorder, previous Achilles tendon injury, hindfoot fracture, leg length discrepancy of more than 0.5 inches, or if the patient were pregnant.  In all, thirty-six of the 58 patients referred for treatment met the inclusion criteria and were assigned to a treatment group based on a computer generated randomized identification number, which the physical therapist was blinded to. In this study, 16 individuals (11 women and five men; average age 51.7 years) were assigned to the experimental group and 20 individuals (15 women and five men; average age 55.3 years) were assigned to the control group.

During the course of treatment, patients were seen for an initial evaluation, then for follow-up at week two, week four, and week six. Patients then continued home-therapy as directed until final follow-up at week 12. The treatment protocol for the control group consisted of gastrocnemius, soleus, and hamstring stretches (three repetitions each twice daily), ice massage of the Achilles tendon for 5-10 minutes twice per day, use of bilateral heel lifts, and use of a resting night splint. The protocol for the experimental group was the same as the control group with the addition of two eccentric strengthening exercises. Both of these exercises consisted bearing weight on the affected foot in a plantarflexed position before slowly lowering the heel into dorsiflexion. One exercise was performed with the knee on the affected side slightly bent, and the other was performed with the knee straight.

Results: Data was collected at the four clinic locations by trained foot and ankle orthopaedic surgeons who were blinded to the treatment protocol that was being followed. Outcome measures were collected at the initial visit when the diagnosis was made, at six weeks, and at 12 weeks. Outcomes were measured using several standardized instruments including the Short Form Health Survey (SF-36), the SF-36 Bodily Pain Subscale, the Foot and Ankle Outcomes Questionnaire (FAOQ), and the visual analog scale (VAS).

Overall, significant improvement was noted in both treatment groups. Improvement was noted in 86.7 percent of patients based on the VAS, in 84.2 percent of patients based on the SF-36, in 73.7 percent of patients based on the SF-36 bodily pain subscale, and in 93.3 percent of patients based on the FAOQ. Additionally, patients in both protocols had significantly improved ankle joint dorsiflexion range of motion and improved gastrocnemius manual muscle strength at the time of their final follow-up. This study found, however, no statistically significant differences between outcomes in the two treatment protocols. Further, this study found no statistically significant differences in outcomes based on age, race, BMI, duration of symptoms, or prior activity level between the groups.

Conclusions: The authors’ hypothesis that the addition of eccentric strengthening to a conventional physical therapy program would be more effective than conventional physical therapy alone in the treatment of insertional Achilles tendinopathy was not supported by the results of this study. The authors did demonstrate, however, that conventional physical therapy, with or without the addition of eccentric training, is an effective treatment modality for insertional Achilles tendinopathy in this particular patient population.