Do athletes alter their running mechanics after an Achilles tendon rupture?

Abstract

BackgroundOver the past thirty years, there has been dramatic increase in incidence of Achilles tendon rupture in the athletic population. The purpose of this study was to compare the lower extremity mechanics of Achilles tendon ruptured runners with healthy controls.MethodsThe participants with a past history of an Achilles tendon repair (n = 11) and healthy control (n = 11) subgroups were matched on sex, age, type of regular physical activity, mass, height, footfall pattern and lateral dominancy. Running kinetics and kinematics of the ankle, knee and hip were recorded using a high-speed motion capture system interfaced with a force platform. Achilles tendon length was measured using ultrasonography. Main outcome measures were lower extremity joint angles and moments during stance phase of running and Achilles tendon lengths.ResultsAthletes from Achilles tendon group had an affected gastro-soleus complex. Athletes with history of Achilles tendon rupture had reduced ankle range of motion during second half of the stance phase of running (Δ7.6°), an overextended knee during initial contact (Δ5.2°) and increased affected knee range of motion (Δ4.4°) during the first half of stance phase on their affected limb compared to the healthy control group. There was a 22% increase in the maximal hip joint moment on contralateral side of the Achilles tendon group compared to the healthy controls.ConclusionThese results suggest a compensation mechanism, relatively extended knee at initial ground contact against the deficit in the muscle-tendon complex of the triceps surae. Overextension during sporting activities may place the knee at risk for further injury. Avoidance of AT lengthening and plantarflexion strength deficit after surgery and during rehabilitation might help to manage AT rupture since these factors may be responsible for altered running kinematics.

Knee Joint Kinematics and Kinetics During Walking and Running After Surgical Achilles Tendon Repair

“…This finding supports previous research that links AT elongation and a plantar flexor deficit with knee extension. 16 The results of this study suggest that runners with AT ruptures have increased knee extension during shod running, possibly to ensure sufficient tension of the elongated gastrocsoleus complex during initial ground contact. 16 As a 2-joint muscle, the gastrocnemius plays an important role as a stabilizer against overextension of the knee and anterior knee laxity.…”

“… 41 Although our results differ from those of some published studies, 7 , 41 they are consistent with others. 1 , 16 The cause of inconsistency could be the different physical activity levels of the participants. While Willy et al 41 studied patients with AT ruptures treated operatively and nonoperatively (mean age, 48 ± 10.9 years; mean time after AT rupture, 6.2 ± 2 years; mean FAOS Sports score, 89.1 ± 13.5; mean ATRS total score, 87.0 ± 13.7), in our study, we studied athletes with operatively treated AT ruptures (mean age, 34.0 ± 8.6 years ; mean time after AT surgery, 6.1 ± 3.7 years; mean FAOS Sports score, 76.0 ± 12.4; mean ATRS total score, 71.1 ± 22.2).…”

“…An a priori sample size estimation was conducted based on a selected key variable (knee internal abduction moment) from a pilot study. 16 A power analysis was performed for 2-way analysis of variance (2 × 2) with a power of 85% and alpha of 0.05. The results of the power analysis determined that a minimum sample size of 18 participants would be required.…”

“… 4 Additionally, bilateral deficits in ankle joint proprioception, as reported in a study by Bressel et al, 6 suggest that the uninvolved limb may not serve as an effective control. The first running-related AT study with a control group was reported by Jandacka et al 16 This sagittal plane–only study has been unable to demonstrate overloading of the affected knee as reported by previous researchers. 36 , 41 …”

“…Therefore, the purpose of this study was to compare the kinematics and kinetics of barefoot walking and barefoot and shod running between athletes with a history of surgically repaired AT ruptures and a healthy control group. Based on previous case studies 17 , 18 , 36 and studies on barefoot running, 2 , 15 , 37 we hypothesized that there would be increased sagittal and frontal 16 knee joint moments in the affected limb of the AT rupture group, especially during shod running.…”