Midportion Achilles tendinopathy (MAT) is a common overuse injury of the lower extremity characterized by the presence of pain, restricted function and interruption of sport activities. Conservative management of MAT has been suggested as the first line of treatment. Actually, there are several exercise programs with beneficial effects on pain and function among which high load training stands out. However, this training modality is inherently difficult to implement in certain populations and pathological conditions due to their inability to tolerate this mechanical stress. In this sense, low load training with blood flow restriction (BFR-LLT) emerges as an effective option in producing hypertrophic adaptations with low intensities (30% 1RM). However, this training modality has not yet been studied in tendon pathology. The aim of this study is to evaluate the potential clinical effects of BFR-LLT in comparison with HLT in patients with chronic MAT.
The aim of this study will be to evaluate the potential clinical effects of low load training with blood flow restriction (BFR-LLT) in comparison with high load training (HLT) in patients with chronic midportion Achilles tendinopathy (MAT). The secondary objectives will be to determine if there are differences in the neovascularity and thickness, pain and function of the AT between both groups in each instance of evaluation. This study will be a simple-blinded randomized clinical trial comprising a total sample size of 52 participants with MAT of both genders and aged between 18 and 50 years. Subjects will undergo a screening process by a sports medicine doctor by different diagnostic tests to identify those presenting a diagnosis of painful MAT and then, they will be randomized into either a group performing HLT (G1), or a group performing BFR-LLT (G2). These volunteers will be recruited in the Parque Hospital (Rosario, Argentine). The study will assess the subjects tendon pain, thickness, cross sectional area and neovascularity, lower limb function, calf raise endurance and jump height. The training protocol will be performed in the University of Gran Rosario (Rosario, Argentine) and will consist of three weekly training sessions during a 12-week rehabilitation period. Primary and secondary outcomes will be measured at baseline, 6 and 12 weeks. All the evaluations will be performed by a blinded physiotherapist.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
52
A 12-cm-wide pneumatic nylon tourniquet will be proximally positioned with a snug fit on each thigh. Previously, arterial occlusion pressure (AOP) will be determined using a handheld Doppler Ultrasound in a standing position for each participant. For training routines, cuff pressure will be set to 50% of each individual´s AOP and will be keep inflated during the entire session including the interset rest period of 1 minute. Between the two exercises, the cuff will be deflated for 3 minutes.
All participants in this arm will do two exercises, unilateral dynamic standing and sitting calf-raises, with a training load of 70% 1RM, being progressively increased by 5% every four weeks from 70% to 80%. This protocol will consist of three sets of 6-12 repetitions with a interset rest period of 1 minute and 3 minutes rest between exercises.
University of Gran Rosario
Rosario, Santa Fe Province, Argentina
RECRUITINGChange on pain intensity
The Numerical Pain Rating Scale (NPRS) will be used to assess pain intensity in daily and sport activities. This scale consists of a sequence of numbers from 0 to 10, in which 0 represents "no pain" and 10 represents "worst pain imaginable".
Time frame: At baseline, then at 6 and 12 weeks
Change on Victorian Institute of Sport Assessment- Achilles Specific Questionnaire (VISA-A)
This questionnaire will be used to assess the symptoms, function and pain during daily living and sport activities. The VISA-A consists of 8 questions in which the patients rate the magnitude of pain during rest, function, and activity. The maximum score is 100 points, and a lower score indicates more symptoms and a greater limitation of function and activity.
Time frame: At baseline, then at 6 and 12 weeks
Change on thickness of the Achilles tendon
Real time ultrasonography will be performed on the injured Achilles tendon in a longitudinal plane. The thickest point of the tendon will be identified and the A-P distance will be measured (12MHZ linear transducer; Toshiba Aplio300).
Time frame: At baseline and 12 weeks
Change on cross sectional area of the Achilles tendon
Real time ultrasonography will be performed on the injured Achilles tendon in a transverse plane. The thickest point of the tendon will be identified and the A-P distance will be measured (12MHZ linear transducer; Toshiba Aplio300).
Time frame: At baseline and 12 weeks
Change on neovascularization of the Achilles tendon
Real time ultrasonography with PowerDoppler will be performed in a longitudinal and transverse planes (12MHZ linear transducer; Toshiba Aplio300).
Time frame: At baseline and 12 weeks
Change on single leg vertical jump
This test will assess the height in cm, power, strength, velocity and flight time of a vertical jump using the My Jump app, validated by Gallardo-Fuentes in 2016. The instructions will be jumping as high as possible with hands on the subject's waist. Participants will perform 3 repetitions in a non-consecutive manner.
Time frame: At baseline, then at 6 and 12 weeks
Change on single leg calf-raise endurance test
This test will assess height, power and work of the calf raise performance during the heel elevation using the Calf Raise app. The test involves going up on the toes and back down as many times the participant can. The test has excellent reliability and is able to detect side-to-side deficits. Participant will be encourage to perform the maximal repetitions during one minute.
Time frame: At baseline, then at 6 and 12 weeks
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