Calf Muscle Performance Deficits Remain 7 Years After an Achilles Tendon Rupture

Am J Sports Med. 2018 Feb;46(2):470-477. doi: 10.1177/0363546517737055. Epub 2017 Oct 25.

Abstract

Background: Optimizing calf muscle performance seems to play an important role in minimizing impairments and symptoms after an Achilles tendon rupture (ATR). The literature lacks long-term follow-up studies after ATR that describe calf muscle performance over time.

Purpose: The primary aim was to evaluate calf muscle performance and patient-reported outcomes at a mean of 7 years after ATR in patients included in a prospective, randomized controlled trial. A secondary aim was to evaluate whether improvement in calf muscle performance continued after the 2-year follow-up.

Study design: Cohort study; Level of evidence, 2.

Methods: Sixty-six subjects (13 women, 53 men) with a mean age of 50 years (SD, 8.5 years) were evaluated at a mean of 7 years (SD, 1 year) years after their ATR. Thirty-four subjects had surgical treatment and 32 had nonsurgical treatment. Patient-reported outcomes were evaluated with Achilles tendon Total Rupture Score (ATRS) and Physical Activity Scale (PAS). Calf muscle performance was evaluated with single-leg standing heel-rise test, concentric strength power heel-rise test, and single-legged hop for distance. Limb Symmetry Index (LSI = injured side/healthy side × 100) was calculated for side-to-side differences.

Results: Seven years after ATR, the injured side showed decreased values in all calf muscle performance tests ( P < .001-.012). Significant improvement in calf muscle performance did not continue after the 2-year follow-up. Heel-rise height increased significantly ( P = .002) between the 1-year (10.8 cm) and the 7-year (11.5 cm) follow-up assessments. The median ATRS was 96 (of a possible score of 100) and the median PAS was 4 (of a possible score of 6), indicating minor patient-reported symptoms and fairly high physical activity. No significant differences were found in calf muscle performance or patient-reported outcomes between the treatment groups except for the LSI for heel-rise repetitions.

Conclusion: Continued deficits in calf muscle endurance and strength remained 7 years after ATR. No continued improvement in calf muscle performance occurred after the 2-year follow-up except for heel-rise height.

Keywords: Achilles tendon rupture; calf muscle performance; heel-rise test; long-term follow-up.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Achilles Tendon / surgery
  • Adult
  • Aged
  • Exercise Test
  • Female
  • Follow-Up Studies
  • Humans
  • Leg
  • Male
  • Middle Aged
  • Muscle Strength
  • Muscle, Skeletal / physiopathology*
  • Patient Reported Outcome Measures
  • Prospective Studies
  • Recovery of Function
  • Rupture / physiopathology*
  • Rupture / surgery
  • Tendon Injuries / physiopathology*
  • Tendon Injuries / surgery
  • Treatment Outcome