The Effect of Loading Speed and Intensity During Exercise on the Immediate Changes in Achilles Tendon Thickness and Stiffness: a Randomised Crossover Trial
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University Hospital, Ghent
- Enrollment
- 34
- Locations
- 1
- Primary Endpoint
- Achilles tendon thickness
Study Overview
Brief Summary
Aim: To assess the influence of loading speed and intensity during eccentric heel drop exercise on the immediate changes in Achilles tendon thickness and stiffness in healthy controls.
Intervention: Three eccentric heel drop exercise protocols, different in loading speed and/or loading intensity will be compared. Each participant will perform a single protocol per session in a random sequence at 1-week intervals.
Participants: a total of 34 healthy athletes will be included.
Outcome measure: tendon thickness and stiffness will be measured at baseline and immediately following intervention with ultrasound imaging (B-mode) and shear wave elastography, respectively.
Discussion: the study will determine whether an eccentric exercise intervention involving a low loading speed and high intensity could maximize the immediate reduction in thickness and associated increase in stiffness of the Achilles tendon compared with interventions involving a higher loading speed and lower intensity.
Detailed Description
Mechanical loading of the Achilles tendon during isolated eccentric contractions induces immediate changes in its structural properties. However, it is not known whether the loading speed and intensity has any impact on these changes. Therefore, this study aims to investigate the influence of loading speed and intensity during eccentric heel drop exercises on the immediate changes in Achilles tendon thickness and stiffness in healthy controls.
Each participant will perform eccentric heel-drops on their dominant leg with and a fully extended knee, and with additional 20% body weight (added via a weighted backpack). Participants will stand with the forefoot of the tested limb on the edge of a step, with the ankle maximally plantar flexed and with body weight centred on this limb. Eccentric loading occurs when the participant lowers the heel to a predetermined angle and speed (depending on the type of intensity and speed cfr infra). In order to return to baseline, the body mass will therefore be shifted to the non-dominant leg to raise the body. Visual feedback (monitor) will be in front of the subjects and the exercise parameters (velocity and ankle angle) will be guided by software guidelines (Ultium Motion).
Three protocols will be compared that differ in execution speed (namely a fast protocol; 1 Hz: 1 second per repetition versus a slow protocol; 0.33 Hz: 3 seconds per repetition) and loading intensity (namely heavy; exercise into maximal dorsiflexion versus light; exercise into neutral ankle position).
Protocol 1 (=Heavy x Slow): subjects perform eccentric heel drops from a maximal plantarflexion position to a maximal dorsiflexion position at a speed of 0.33 Hz, i.e. 3 seconds per movement cycle.
Protocol 2 (=Heavy x Fast): subjects perform eccentric heel drops from a maximal plantarflexion position to a maximal dorsiflexion position at a speed of 3 Hz, i.e. 1 seconds per movement cycle.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Treatment
- Masking
- Single (Outcomes Assessor)
Masking Description
The outcome assessor was blinded to the specific intervention (protocol type); due to the nature of the interventions, participants were aware of the exercise intervention they were performing each week. However, participants will not be informed of the hypothesis of the study nor will this be disclosed at any time in written materials or verbal interactions.
Eligibility Criteria
- Ages
- 18 Years to 55 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age 18 to 55 years
- •Participate in recreational or competitive sport (at least 1x/week)
Exclusion Criteria
- •History of Achilles tendinopathy
- •Presence of rheumatological disease
- •Not able to complete an exercise programme
Arms & Interventions
Slow and heavy exercise therapy
Participants perform eccentric heel drop exercises into maximal dorsiflexion at slow speed.
Intervention: Slow and heavy exercise therapy (Other)
Slow and light exercise therapy
Participants perform eccentric heel drop exercises into neutral ankle position at slow speed.
Intervention: Slow and light exercise therapy (Other)
Fast and heavy exercise therapy
Participants perform eccentric heel drop exercises into maximal dorsiflexion at fast speed.
Intervention: Fast and heavy exercise therapy (Other)
Outcomes
Primary Outcomes
Achilles tendon thickness
Time Frame: Baseline and immediately following each protocol
Tendon anteroposterior diameter will be assessed 20 mm proximal to the posterosuperior calcaneal border using ultrasound imaging. The Achilles tendon is scanned at rest with the subject in the prone position and the foot passively maintained in a neutral position.
Achilles tendon cross-sectional area
Time Frame: Baseline and immediately following each protocol
Tendon cross-sectional area of the Achilles tendon will be assessed 20 mm proximal to the posterosuperior calcaneal border using ultrasound imaging. The Achilles tendon is scanned at rest with the subject in the prone position and the foot passively maintained in a neutral position.
Achilles tendon stiffness
Time Frame: Baseline and immediately following each protocol
Echogenicity of the Achilles tendon will be assessed 20 mm proximal to the posterosuperior calcaneal border using shear wave elastography. The Achilles tendon is scanned at rest with the subject in the prone position and the foot passively maintained in a 30° plantar flexion.
Secondary Outcomes
No secondary outcomes reported