Muscular Morphomechanical Characteristics After an Achilles Repair

Abstract

Background: The purpose of the study was to compare the morphomechanical and functional characteristics during maximal isometric, concentric, and eccentric contractions in the legs of patients that underwent unilateral Achilles tendon repair with those in their noninjured control legs. Methods: Twenty participants (median age = 38.2 years; range, 21.1-57.3 years) who underwent Achilles repair between 3 and 12 months ago were recruited with the following measures: (1) mechanical stiffness of the aponeurosis and (2) electromyography and medial gastrocnemius fascicle angle and length, standing muscle and tendon length, and height of heel rise with isometric contraction. Results: Compared to the noninjured legs, the repaired legs showed less resting fascicle length, standing muscle length, isometric plantarflexion torque, and heel raise distance ( Ps ranged between .044 and <.001). During the concentric and eccentric phases of the raising and lowering test, the repaired legs demonstrated less fascicle length ( P ≤ .028) but greater tendinous tissue length ( Ps ranged between .084 and <.001) and fascicle angle ( Ps ranged between .247 and .008) and fewer change magnitudes of the fascicle length and tendinous tissue length ( P ≤ .003). The change magnitudes of the morphological characteristics showed correlations with the torque or distance. Conclusion: Selecting the appropriate surgical repair and rehabilitation for Achilles tendon ruptures is recommended for restoring the length and mechanical strength of the muscle-tendon unit of plantar-flexion muscles. Level of Evidence: Level III, comparative study.

Gastrocnemius muscle remodeling explains functional deficits three months following Achilles tendon rupture

“…While, we plan to collect 1-year follow-up data on these patients, the purpose of this study was to determine the relationship between muscle remodeling and functional deficits when patients are cleared to return to activity. Similar decreases in gastrocnemius fascicle length up to 12 months following rupture have been reported, 10 suggesting that the changes in muscle structure are permanent. We decided to image the medial gastrocnemius because it has longer, less pennate fascicles that are better suited for generating power in ankle plantarflexion compared to the soleus.…”

“…Similar observations were reported in patients treated surgically 3-12 months following treatment. 10 Clinical treatment is targeted at minimizing tendon elongation following rupture, which can be targeted with early ankle motion 5 and avoiding immobilization in dorsiflexion. 26 Conversely, high velocity training stimulates longer muscle fascicles in a bipedal bird model.…”

“…8 Single-leg heel raise height is positively correlated with resting gastrocnemius length 9 and active shortenng. 10 Following Achilles tendon ruptures, patients have compromised plantarflexor function and compensate by increasing the work done by the proximal knee joint. 11 Gastrocnemius muscle remodeling occurs following Achilles tendon ruptures, 12,13 which appears to be in response to a sudden loss of muscle-tendon tension.…”

Muscle structure governs joint function: linking natural variation in medial gastrocnemius structure with isokinetic plantar flexor function

“…We decided to measure the structure of the medial gastrocnemius due to previous observations linking structural changes in that muscle following Achilles tendon rupture to functional deficits (Baxter et al, 2018; Hullfish et al, 2019b) coupled with similar observations with other studies (Peng et al, 2017, 2019). Prior studies have linked plantar flexor torque measurements with medial gastrocnemius structure without accounting for the other two triceps surae muscles (Hauraix et al, 2015; Thom et al, 2007).…”

A Pilot Study of Musculoskeletal Abnormalities in Patients in Recovery from a Unilateral Rupture-Repaired Achilles Tendon

“…The average ATRS value of the previous study is 87.0 compared with 83.7 in this study, and the follow-up time of the previous study was 6.2 years on average compared to two years in our study. Probably, the AT of the patients in this study were still in the remodeling stage and the symptoms and functions will reach a plateau two years after ATR [46]. The greater knee/patellofemoral joint loading was reported positively correlated with patellofemoral pain and even knee osteoarthritis in previous studies [47,48].…”