Eccentric Training Effects on Functionality and Neuromechanical Properties After Achilles Tendon Surgical Repair

Federal University of Rio Grande do Sul

Status: Completed

Conditions: Achilles Tendon Rupture

Treatments: Other: Isokinetic eccentric training; Other: Traditional eccentric training

Study type: Interventional

Funder types: Other

Identifiers

NCT03861572

UFRGS 3.046.049

Details and patient eligibility

About

Early rehabilitation protocols have been studied in Achilles tendon (AT) rupture patients, but deficits in tendon biomechanical properties have been observed several years after the injury. AT rupture patients are unable to return to their previous levels of physical activity. They present deleterious adaptations in the plantar flexor muscles that lead to functional deficits, and deficits in the tendon's structural and mechanical properties. Eccentric contractions have been suggested to recover these muscle properties. This contraction is known to produce higher force compared to isometric and concentric contractions, and increases tendon stiffness. However, there is a lack of studies showing the effects of the eccentric training in AT rupture rehabilitation. We want to know if an isokinetic eccentric training program will determine the desired adaptations on triceps surae muscle-tendon unit's properties in patients subjected to the AT surgical repair. More specifically, the aim of this study is verifying the effects of a 12-week eccentric training program on triceps surae muscle-tendon unit's properties in subjects that were subjected to the AT surgical repair. 30 subjects will be randomized in two groups: (1) isokinetic eccentric training; and (2) traditional eccentric training control group. All participants will be submitted to a four-week control period, followed by a 12-week period of training for the plantar flexor muscles. Neuromuscular system properties, AT biomechanical properties and functional tests will be evaluated. Participants will be evaluated in four moments: at baseline; after 4, 8 and 12 weeks of rehabilitation. Tendon mechanical (stiffness, stress, strain), material (Young's modulus) and morphological (cross-sectional area and tendon length) properties; muscle architecture (thickness, pennation angle and fascicle length); and functional tests (heel rise resistance and height) will be analyzed between groups and periods. Effects and interactions will be analyzed with ANOVA two-way. Clinical effects will be analyzed using effect size and magnitude-based inferences.

Full description

Detailed Description: Early rehabilitation protocols have been studied in Achilles tendon (AT) rupture patients, but deficits in tendon biomechanical properties have been observed several years after the injury. AT rupture patients are unable to return to their previous levels of physical activity. They present deleterious adaptations in the plantar flexor muscles that lead to functional deficits and deficits in the tendon structural and mechanical properties. Deficits in calf muscle endurance and strength remained 7 years after the injury. In this regards, eccentric contractions are recommended to recover muscle morphology and mechanical properties. This contraction type produces higher force compared to isometric and concentric contractions, and increases tendon stiffness. However, there is a lack of studies showing the effect of the eccentric training in AT rupture rehabilitation. We want to know if an isokinetic eccentric training program will determine the desired adaptations on triceps surae muscle-tendon unit's properties in patients subjected to the AT surgical repair. More specifically, the aim of this study is verifying the effects of a 12-week eccentric training program on triceps surae muscle-tendon unit's properties in subjects that were subjected to the AT surgical repair. Our hypothesis is that the eccentric training program will (1) increase the ability to produce muscular strength; (2) will produce an increase in gastrocnemius and soleus muscles thickness, fascicle length, and pennation angle; (3) will increase AT stiffness and Young's modulus; (4) will increase ankle functionality; (5) will improve the patient's quality of life. Finally, we expect that the abovementioned changes from isokinetic eccentric training will be greater than those from the traditional eccentric control group that will be subjected to 12 weeks of plantar flexor training with weights. 30 subjects will be randomized in two groups: (1) isokinetic eccentric training; and (2) traditional eccentric training control group. All participants will be submitted to a four-week control period, followed by a 12- week period of training for the plantar flexor muscles. Neuromuscular system properties, AT biomechanical properties and functional tests will be evaluated. Participants will be evaluated in four moments: at baseline; after 4, 8 and 12 weeks of rehabilitation. Tendon mechanical (stiffness, stress, strain), material (Young's modulus) and morphological (cross sectional area and tendon length) properties; muscle architecture (thickness, pennation angle and fascicle length); and functional tests (heel rise resistance and height) will be analyzed between groups and periods. Effects and interactions will be analyzed with ANOVA two- way (group x period). Clinical effects will be analyzed using effect size (Cohen's d) and magnitude-based inferences.

Enrollment: 33 patients

Sex: All

Ages: 25 to 50 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Participants will be male and female subjects who suffered total acute Achilles tendon rupture, and which underwent surgical repair. In addition, to participate in this study all volunteers will need to present medical and/or physiotherapeutic release for physical/sports activities practice.

Exclusion criteria

• Volunteers that did not have Achilles tendon surgical reconstruction, that did not present medical and/or physiotherapeutic release for physical/sports activities, who have participated in strength training program for the plantar flexors in the last 6 months, patients with diabetic diseases, as well as those with difficulty for understanding and/or executing the test and training protocols in the isokinetic dynamometer will be excluded.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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33 participants in 2 patient groups

Isokinetic eccentric group

Experimental group

Description:

The isokinetic eccentric training will be carried out with the volunteers positioned seated on the dynamometer with the apparent axis of the ankle joint rotation aligned with the dynamometer's axis of rotation. Movement will be executed in the angular velocity of 30°·s-1. Ankle range of motion (ROM) will be standardized for all participants in 50º, which shall respect each individual's maximal dorsiflexion amplitude. The 50° eccentric training ROM will start from each subject's 80% of the maximal dorsiflexion. This procedure will be used to ensure that all subjects perform training on the same plantar flexor muscular length, which should promote the same level of muscular requirement among the participants. This methodology was recently used by GEREMIA and VAZ (2016) study.

Treatment:

Other: Isokinetic eccentric training

Traditional eccentric training

Active Comparator group

Description:

Participants will be engaged in an intervention program consisting of 12 weeks of traditional eccentric training. The training will be carried out with the volunteers at gym in stand position. Concentric phase will be realized with both legs and the eccentric one only with one of them. Training progression will be the same from de isokinetic eccentric group. The same periodization from eccentric group will be used to permit us a posteriori comparison between groups. Training sessions will be performed at university gym, twice a week, with a minimum interval of 72 hours between sessions. Each training session will comprise the same specific warming protocol for the ankle joint from the eccentric training.

Treatment:

Other: Traditional eccentric training