Eccentric vs. Concentric Training in Achilles Tendinitis

Superior short-term results with eccentric calf muscle training compared to concentric training in a randomized prospective multicenter study on patients with chronic Achilles tendinosis. Mafi N, Lorentzon R, Alfredson H. Knee Surg Sports Traumatol Arthrosc. 2001;9(1):42-47.


In a previous uncontrolled pilot study we demonstrated very good clinical results with eccentric calf muscle training on patients with painful chronic Achilles tendinosis located at the 2-6 cm level in the tendon. In the present prospective multicenter study (Sundsvall and Umeå) patients with painful chronic Achilles tendinosis at the 2-6 cm level in the tendon were randomized to treatment with either an eccentric or a concentric training regimen for the calf muscles. The study included 44 patients, with 22 patients (12 men, 10 women; mean age 48 years) in each treatment group. The amount of pain during activity (jogging or walking) was recorded by the patients on a visual analogue scale, and patient satisfaction was assessed before and after treatment. The patients were instructed to perform their eccentric or concentric training regimen on a daily basis for 12 weeks. In both types of treatment regimen the patients were told to do their exercises despite experiencing pain or discomfort in the tendon during exercise. The results showed that after the eccentric training regimen 82% of the patients (18/22) were satisfied and had resumed their previous activity level (before injury), compared to 36% of the patients (8/22) who were treated with the concentric training regimen. The results after treatment with eccentric training was significantly better (P<0.002) than after concentric training. The good clinical results previously demonstrated in the pilot study with eccentric calf muscle training on patients with chronic Achilles tendinosis, were thus reproduced in this multicenter, showing superior results to treatment with concentric training.

Diagnosis:  Mid portion tendinitis (2-6 cm above insertion)

Outcome:  VAS during running or walking, 82% of eccentric group returned to previous activity level (PAL) with VAS decreasing from 69 to 12, of those that did not return to PAL VAS decrease to 44. 36% of concentric group achieved PAL with VAS decreased from 63 to 9, while non-responders went to 60.

When Assessed:  12 weeks

Subjects:  Eccentric group 12 men & 10 women, ave age 48 . Concentric group 12 men 10 women, ave age 48.

Protocol:  Eccentric: 2 exercises (one with knee straight and one with knee bent) 3×15 each, 2 x per day, 7 days per week for 12 weeks, starting with full body weight on one leg, train with pain unless “disabling”, no indication of varied speed. Concentric: 2 to 3 sets of 15-20 repetitions of concentric calf raises with theraband, seated calf raises without resistance, standing heel raises, step ups on a bench, jump rope and lateral hops. Higher impact/functional exercises added after 4 weeks.

Other Activity:  Running allowed to continue if “with only mild discomfort and no pain.” “The patients were instructed to start jogging or walking activity at a slow pace, on flat ground, and for a short distance. Thereafter their activity could be gradually increased if there was no severe pain in the tendon.

Chad’s Comments:  Concentric group did not seem to be as steady or structured as program as the eccentric group. Not so sure about 48 year old patients jumping rope.

As always, if you have any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.

Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.

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