Achilles Tendon RuptureNCT06912269
Effects of Strength Training on the Plantar Flexors' Properties After Achilles Tendon Rupture
A study testing Exercise in people with Achilles Tendon Rupture and Strength Training Adaptations, run by Federal University of Rio Grande do Sul at 1 site in Brazil.
Trial summary
Among the injuries that affect the Achilles tendon, rupture is one of the most frequent. This injury can generate functional, neuromuscular, and tendon deficits that can last for long periods or even be permanent. Read more about this study
- Who is it for?
- Ages 18 to 64 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Achilles Tendon Rupture, Strength Training Adaptations, Neuromuscular Adaptations
- What is being tested?
- Exercise
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 67 participants
- Where
- 1 siteBrazil
- Study dates
- 10 Oct 2024to 30 Aug 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men aged 18 to 64 who have ruptured their Achilles tendon unilaterally no more than 5 years ago;
- Who are not performing systematic and regular calf strength training.
Who cannot join
- Non-surgical treatment for Achilles tendon rupture;
- History of postsurgical complications (infection or re-rupture);
- Presence of any type of ankle injury in the last six month;
- Participation in a strength training program for plantar flexors in the last six months prior to participation in the study;
- Having heart failure; autoimmune diseases; and/or diabetes;
- Systematic use of antibiotics or steroids within the last 12 months;
- Presence of any other clinical contraindication for performing maximum strength tests.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Brazil1 site, 1 recruiting
- Recruiting
Exercise Research Laboratory (LAPEX) - School of Physical Education, Physiotherapy, and Dance
Porto Alegre, Rio Grande do Sul, 90690-200
Jeam M Geremia, PhD, +5505133085852, jeam.geremia@ufrgs.br
About this study
Official title: Effects of Strength Training at Different Intensities on the Plantar Flexors' Functional, Neuromuscular, and Tendon Properties After Achilles Tendon Rupture
Among the injuries that affect the Achilles tendon, rupture is one of the most frequent. This injury can generate functional, neuromuscular, and tendon deficits that can last for long periods or even be permanent. In the long term (i.e., more than a year after the injury), individuals present functional impairments related to the lower limb, deficits in the capacity to produce muscle force, as well as higher levels of muscle activation (as a compensatory response). Such changes may be due to injury adaptations in the plantar flexor muscles' architecture, which may have shorter, more pennate fibers, leading to reduced muscle thickness. Furthermore, the Achilles tendon may be elongated, with a greater cross-sectional area, presenting lower stiffness and quality (i.e., lower Young's modulus). Strength training can play an important role in recovering from Achilles tendon ruptures, as it promotes functional, neuromuscular, and tendon adaptations that can minimize deficits caused by the injury. However, there is a gap in the literature regarding strength training, as well as the dose vs response relationship, regarding functional, neuromuscular, and tendon adaptations after Achilles tendon rupture. Thus, the aim of the present study is to compare the effects of a strength training program of different intensities on plantar flexors' functional, neuromuscular, and tendon outcomes after Achilles tendon rupture. Men aged between 20 and 50 years old who suffered a total unilateral rupture of the Achilles tendon between one and five years after the rupture will be included in the study, as well as healthy men who did not suffer the rupture (control group). Participants who have suffered an Achilles tendon rupture will undergo a progressive lower limb strength training program twice a week for a total duration of 12 weeks, which will be randomized between two groups: low intensity (G55 - 55% of 1-RM) and moderate intensity (G70 - 70% of 1-RM). The following outcomes will be evaluated: a) Achilles tendon's morphological (length and cross-sectional area), mechanical (force-elongation relationship and stiffness) and material (stress-strain relationship and Young's modulus) properties; b) triceps surae muscles' morphological (architecture [fascicle length, pennation angle and thickness] and quality [measured by echointensity and specific tension]) properties; c) ankle functionality (maximum height in the heel raise test); d) the plantar flexors' force production capacity (peak and rate of torque development in different joint positions); e) the plantar flexors' muscle voluntary activation; and f) triceps suraes' neuromuscular capacity (i.e., recruitment curves). Assessments will be performed at two times (pre-training; and after 12 weeks of training [post-12]) through functional tests, ultrasound techniques, isokinetic dynamometry, electromyography, and percutaneous electrical stimulation. An intraclass correlation coefficient will be used to verify the test-retest reproducibility of ultrasound measurements. The Chi-Square test will be used to compare the level of physical activity (pre-training) between the groups. The results of the intervention will be expressed using descriptive statistics (mean, standard deviation, and standard error). The normality and sphericity of the data will be tested using the Shapiro-Wilk and Mauchly tests, respectively. A generalized estimating equation, followed by Bonferroni post-hoc, will be used to compare the effects of groups (G55 and G70) and times (pre-training, Post-6, and Post-12). A one-way ANOVA, followed by a Bonferroni post-hoc, will be used to compare the control group participants' limbs with the healthy and injured limbs from both intervention groups (G55 and G70) in the Pre and Post-12 times. The effect size will be estimated for each outcome. All statistical analyzes will be performed using SPSS software.
Read the detailed description
Among the injuries that affect the Achilles tendon, rupture is one of the most frequent. This injury can generate functional, neuromuscular, and tendon deficits that can last for long periods or even be permanent. In the long term (i.e., more than a year after the injury), individuals present functional impairments related to the lower limb, deficits in the capacity to produce muscle force, as well as higher levels of muscle activation (as a compensatory response). Such changes may be due to injury adaptations in the plantar flexor muscles' architecture, which may have shorter, more pennate fibers, leading to reduced muscle thickness. Furthermore, the Achilles tendon may be elongated, with a greater cross-sectional area, presenting lower stiffness and quality (i.e., lower Young's modulus). Strength training can play an important role in recovering from Achilles tendon ruptures, as it promotes functional, neuromuscular, and tendon adaptations that can minimize deficits caused by the injury. However, there is a gap in the literature regarding strength training, as well as the dose vs response relationship, regarding functional, neuromuscular, and tendon adaptations after Achilles tendon rupture. Thus, the aim of the present study is to compare the effects of a strength training program of different intensities on plantar flexors' functional, neuromuscular, and tendon outcomes after Achilles tendon rupture. Men aged between 20 and 50 years old who suffered a total unilateral rupture of the Achilles tendon between one and five years after the rupture will be included in the study, as well as healthy men who did not suffer the rupture (control group). Participants who have suffered an Achilles tendon rupture will undergo a progressive lower limb strength training program twice a week for a total duration of 12 weeks, which will be randomized between two groups: low intensity (G55 - 55% of 1-RM) and moderate intensity (G70 - 70% of 1-RM). The following outcomes will be evaluated: a) Achilles tendon's morphological (length and cross-sectional area), mechanical (force-elongation relationship and stiffness) and material (stress-strain relationship and Young's modulus) properties; b) triceps surae muscles' morphological (architecture [fascicle length, pennation angle and thickness] and quality [measured by echointensity and specific tension]) properties; c) ankle functionality (maximum height in the heel raise test); d) the plantar flexors' force production capacity (peak and rate of torque development in different joint positions); e) the plantar flexors' muscle voluntary activation; and f) triceps suraes' neuromuscular capacity (i.e., recruitment curves). Assessments will be performed at two times (pre-training; and after 12 weeks of training [post-12]) through functional tests, ultrasound techniques, isokinetic dynamometry, electromyography, and percutaneous electrical stimulation. An intraclass correlation coefficient will be used to verify the test-retest reproducibility of ultrasound measurements. The Chi-Square test will be used to compare the level of physical activity (pre-training) between the groups. The results of the intervention will be expressed using descriptive statistics (mean, standard deviation, and standard error). The normality and sphericity of the data will be tested using the Shapiro-Wilk and Mauchly tests, respectively. A generalized estimating equation, followed by Bonferroni post-hoc, will be used to compare the effects of groups (G55 and G70) and times (pre-training, Post-6, and Post-12). A one-way ANOVA, followed by a Bonferroni post-hoc, will be used to compare the control group participants' limbs with the healthy and injured limbs from both intervention groups (G55 and G70) in the Pre and Post-12 times. The effect size will be estimated for each outcome. All statistical analyzes will be performed using SPSS software.
- Being tested
- Exercise
- Keywords
- Neuromuscular plasticity, Stiffness, Functionality, Triceps surae, Calcaneal tendon rupture
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ExerciseOther
A progressive calf strength training program lasting 12 weeks (twice weekly sessions), with a total of 25 visits to the gym. Specific exercises for ankle flexors: standing unilateral plantar flexion (on the machine) and seated unilateral plantar flexion (adapted on the Smith machine) will be performed. Participants will use progressive load from 55% of one repetition maximum load for the specific plantar flexion exercises.
ExerciseOther
A progressive calf strength training program lasting 12 weeks (twice weekly sessions), with a total of 25 visits to the gym. Specific exercises for ankle flexors: standing unilateral plantar flexion (on the machine) and seated unilateral plantar flexion (adapted on the Smith machine) will be performed. Participants will use progressive load from 70% of one repetition maximum load for the specific plantar flexion exercises.
| Study group | Role | What they receive |
|---|---|---|
| Strength training (low intensity) | Experimental | Twelve weeks of strength training program for the calf muscles, with low load intensity Receives: Other: Exercise |
| Strength training (moderate intensity) | Experimental | Twelve weeks of strength training program for the calf muscles, with moderate load intensity Receives: Other: Exercise |
| Healthy subjects | No intervention | A control condition composed of healthy individuals (i.e., without any injury), who will not receive any training, will be used as a comparison at the beginning and end of the intervention. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in foot and ankle joint function
The foot and ankle joint function will be assessed through Foot and Ankle Outcome Score, which evaluate five different domains: pain, other symptoms, activities of daily living, sports and recreational activities, and quality of life related to the ankle and foot.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in Achilles tendon function and symptom
Achilles tendon post-rupture function and symptoms will be assessed through Achilles Tendon Rupture Score (ATRS).
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in ankle functional performance
The ankle functional performance will be assessed using the heel raise test. With this test, the maximum height of the heel lift will be assessed, corresponding to the measurement of functionality of the ankle plantar flexors.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in plantar flexors' muscle strength
The plantar flexors' muscle strength will be assessed by the peak torque in different ankle joints (i.e., -10º, 0º, and 20º of plantar flexion - 0º neutral position).
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in Achilles tendon stiffness
Tendon stiffness will be obtained by calculating the slope in the last 10% of the linear region of the force-deformation curve.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Secondary outcomes (5)
Changes in Achilles tendon Young's Modulus
Tendon stiffness will be obtained by calculating the slope in the last 10% of the linear region of the stress-strain curve.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in Achilles tendon morphological properties
Tendon morphological properties will be obtained by the total tendon length (distance between medial gastrocnemius muscle-tendon junction and tendon distal insertion in the calcaneous bone), free tendon length (soleus muscle-tendon junction and tendon distal insertion), and tendon's cross sectional area (measured at 2, 4, and 6cm from the tendon distal insertion).
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in plantar flexors' muscle arquitecture
The muscular architecture of the plantar flexor muscles will be evaluated using B-mode ultrasound images. Imagem analyses will be performed to identify the pennation angle and length of the muscle fascicles, and the muscle thickness of each triceps surae muscle.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in plantar flexors' muscle activation
Muscle activation will be captured during muscle voluntary isometric contraction (MVIC) testes, at different joint positions. The maximum root mean square (RMS) values of each plantar flexor muscle will be calculated for each of the MVICs produced during the isometric peak torque assessments. These RMS values will be obtained by means of 1-s duration cuts (corresponding to 2000 points) of the MVICs during the torque signal plateau.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in neuromuscular recruitment capacity
Muscle activation parameters evoked by percutaneous neuromuscular electrical stimulation techniques will be obtained through neuromechanical responses. Recruitment curves will be constructed to evaluate the neuromuscular capacity of the plantar flexors, based on the peak-to-peak amplitudes of the M waves and H reflexes, which will be mapped and recorded simultaneously.
Measured: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Apr 2025
- Study start10 Oct 2024
- Primary completion20 Aug 2026 (estimated)
- Study completion30 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Achilles Tendon RuptureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 67 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Federal University of Rio Grande do Sul
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jeam Marcel Geremia, Federal University of Rio Grande do Sul
- Investigators
- Jeam M Geremia, PhD, Study director, Federal University of Rio Grande do SulMarcelo H Glänzel, MSc, Principal investigator, Federal University of Rio Grande do Sul
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06912269
- Sponsor's protocol ID
- 6786944
- Status last verified
- Jan 2026
- First submitted
- 10 Oct 2024
- Last updated
- 30 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 30 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Strength Training at Different Intensities on the Plantar Flexors' Functional, Neuromuscular, and Tendon Properties After Achilles Tendon Rupture
- ClinicalTrials.gov ID
- NCT06912269
- Acronym / sponsor ID
- 6786944
- Keywords
- Neuromuscular plasticity, Stiffness, Functionality, Triceps surae, Calcaneal tendon rupture
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 67 participants (estimated)
- Lead sponsor
- Federal University of Rio Grande do SulUniversity, hospital or other
- Study start
- 10 Oct 2024 (actual)
- Primary completion
- 20 Aug 2026 (estimated)
- Study completion
- 30 Aug 2026 (estimated)
- First posted
- 4 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Among the injuries that affect the Achilles tendon, rupture is one of the most frequent. This injury can generate functional, neuromuscular, and tendon deficits that can last for long periods or even be permanent. In the long term (i.e., more than a year after the injury), individuals present functional impairments related to the lower limb, deficits in the capacity to produce muscle force, as well as higher levels of muscle activation (as a compensatory response). Such changes may be due to injury adaptations in the plantar flexor muscles' architecture, which may have shorter, more pennate fibers, leading to reduced muscle thickness. Furthermore, the Achilles tendon may be elongated, with a greater cross-sectional area, presenting lower stiffness and quality (i.e., lower Young's modulus). Strength training can play an important role in recovering from Achilles tendon ruptures, as it promotes functional, neuromuscular, and tendon adaptations that can minimize deficits caused by the injury. However, there is a gap in the literature regarding strength training, as well as the dose vs response relationship, regarding functional, neuromuscular, and tendon adaptations after Achilles tendon rupture. Thus, the aim of the present study is to compare the effects of a strength training program of different intensities on plantar flexors' functional, neuromuscular, and tendon outcomes after Achilles tendon rupture. Men aged between 20 and 50 years old who suffered a total unilateral rupture of the Achilles tendon between one and five years after the rupture will be included in the study, as well as healthy men who did not suffer the rupture (control group). Participants who have suffered an Achilles tendon rupture will undergo a progressive lower limb strength training program twice a week for a total duration of 12 weeks, which will be randomized between two groups: low intensity (G55 - 55% of 1-RM) and moderate intensity (G70 - 70% of 1-RM). The following outcomes will be evaluated: a) Achilles tendon's morphological (length and cross-sectional area), mechanical (force-elongation relationship and stiffness) and material (stress-strain relationship and Young's modulus) properties; b) triceps surae muscles' morphological (architecture [fascicle length, pennation angle and thickness] and quality [measured by echointensity and specific tension]) properties; c) ankle functionality (maximum height in the heel raise test); d) the plantar flexors' force production capacity (peak and rate of torque development in different joint positions); e) the plantar flexors' muscle voluntary activation; and f) triceps suraes' neuromuscular capacity (i.e., recruitment curves). Assessments will be performed at two times (pre-training; and after 12 weeks of training [post-12]) through functional tests, ultrasound techniques, isokinetic dynamometry, electromyography, and percutaneous electrical stimulation. An intraclass correlation coefficient will be used to verify the test-retest reproducibility of ultrasound measurements. The Chi-Square test will be used to compare the level of physical activity (pre-training) between the groups. The results of the intervention will be expressed using descriptive statistics (mean, standard deviation, and standard error). The normality and sphericity of the data will be tested using the Shapiro-Wilk and Mauchly tests, respectively. A generalized estimating equation, followed by Bonferroni post-hoc, will be used to compare the effects of groups (G55 and G70) and times (pre-training, Post-6, and Post-12). A one-way ANOVA, followed by a Bonferroni post-hoc, will be used to compare the control group participants' limbs with the healthy and injured limbs from both intervention groups (G55 and G70) in the Pre and Post-12 times. The effect size will be estimated for each outcome. All statistical analyzes will be performed using SPSS software.
Detailed description
Among the injuries that affect the Achilles tendon, rupture is one of the most frequent. This injury can generate functional, neuromuscular, and tendon deficits that can last for long periods or even be permanent. In the long term (i.e., more than a year after the injury), individuals present functional impairments related to the lower limb, deficits in the capacity to produce muscle force, as well as higher levels of muscle activation (as a compensatory response). Such changes may be due to injury adaptations in the plantar flexor muscles' architecture, which may have shorter, more pennate fibers, leading to reduced muscle thickness. Furthermore, the Achilles tendon may be elongated, with a greater cross-sectional area, presenting lower stiffness and quality (i.e., lower Young's modulus). Strength training can play an important role in recovering from Achilles tendon ruptures, as it promotes functional, neuromuscular, and tendon adaptations that can minimize deficits caused by the injury. However, there is a gap in the literature regarding strength training, as well as the dose vs response relationship, regarding functional, neuromuscular, and tendon adaptations after Achilles tendon rupture. Thus, the aim of the present study is to compare the effects of a strength training program of different intensities on plantar flexors' functional, neuromuscular, and tendon outcomes after Achilles tendon rupture. Men aged between 20 and 50 years old who suffered a total unilateral rupture of the Achilles tendon between one and five years after the rupture will be included in the study, as well as healthy men who did not suffer the rupture (control group). Participants who have suffered an Achilles tendon rupture will undergo a progressive lower limb strength training program twice a week for a total duration of 12 weeks, which will be randomized between two groups: low intensity (G55 - 55% of 1-RM) and moderate intensity (G70 - 70% of 1-RM). The following outcomes will be evaluated: a) Achilles tendon's morphological (length and cross-sectional area), mechanical (force-elongation relationship and stiffness) and material (stress-strain relationship and Young's modulus) properties; b) triceps surae muscles' morphological (architecture [fascicle length, pennation angle and thickness] and quality [measured by echointensity and specific tension]) properties; c) ankle functionality (maximum height in the heel raise test); d) the plantar flexors' force production capacity (peak and rate of torque development in different joint positions); e) the plantar flexors' muscle voluntary activation; and f) triceps suraes' neuromuscular capacity (i.e., recruitment curves). Assessments will be performed at two times (pre-training; and after 12 weeks of training [post-12]) through functional tests, ultrasound techniques, isokinetic dynamometry, electromyography, and percutaneous electrical stimulation. An intraclass correlation coefficient will be used to verify the test-retest reproducibility of ultrasound measurements. The Chi-Square test will be used to compare the level of physical activity (pre-training) between the groups. The results of the intervention will be expressed using descriptive statistics (mean, standard deviation, and standard error). The normality and sphericity of the data will be tested using the Shapiro-Wilk and Mauchly tests, respectively. A generalized estimating equation, followed by Bonferroni post-hoc, will be used to compare the effects of groups (G55 and G70) and times (pre-training, Post-6, and Post-12). A one-way ANOVA, followed by a Bonferroni post-hoc, will be used to compare the control group participants' limbs with the healthy and injured limbs from both intervention groups (G55 and G70) in the Pre and Post-12 times. The effect size will be estimated for each outcome. All statistical analyzes will be performed using SPSS software.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Strength training (low intensity) | Experimental | Other: ExerciseTwelve weeks of strength training program for the calf muscles, with low load intensity |
| Strength training (moderate intensity) | Experimental | Other: ExerciseTwelve weeks of strength training program for the calf muscles, with moderate load intensity |
| Healthy subjects | No intervention | –A control condition composed of healthy individuals (i.e., without any injury), who will not receive any training, will be used as a comparison at the beginning and end of the intervention. |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Men aged 18 to 64 who have ruptured their Achilles tendon unilaterally no more than 5 years ago;
- Who are not performing systematic and regular calf strength training.
Key exclusion criteria (7 listed)
- Non-surgical treatment for Achilles tendon rupture;
- History of postsurgical complications (infection or re-rupture);
- Presence of any type of ankle injury in the last six month;
- Participation in a strength training program for plantar flexors in the last six months prior to participation in the study;
- Having heart failure; autoimmune diseases; and/or diabetes;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ExerciseA progressive calf strength training program lasting 12 weeks (twice weekly sessions), with a total of 25 visits to the gym. Specific exercises for ankle flexors: standing unilateral plantar flexion (on the machine) and seated unilateral plantar flexion (adapted on the Smith machine) will be performed. Participants will use progressive load from 55% of one repetition maximum load for the specific plantar flexion exercises. | Other | Strength training (low intensity) |
| ExerciseA progressive calf strength training program lasting 12 weeks (twice weekly sessions), with a total of 25 visits to the gym. Specific exercises for ankle flexors: standing unilateral plantar flexion (on the machine) and seated unilateral plantar flexion (adapted on the Smith machine) will be performed. Participants will use progressive load from 70% of one repetition maximum load for the specific plantar flexion exercises. | Other | Strength training (moderate intensity) |
Primary outcome
Changes in foot and ankle joint function
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
The foot and ankle joint function will be assessed through Foot and Ankle Outcome Score, which evaluate five different domains: pain, other symptoms, activities of daily living, sports and recreational activities, and quality of life related to the ankle and foot.
Changes in Achilles tendon function and symptom
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Achilles tendon post-rupture function and symptoms will be assessed through Achilles Tendon Rupture Score (ATRS).
Changes in ankle functional performance
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
The ankle functional performance will be assessed using the heel raise test. With this test, the maximum height of the heel lift will be assessed, corresponding to the measurement of functionality of the ankle plantar flexors.
Changes in plantar flexors' muscle strength
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
The plantar flexors' muscle strength will be assessed by the peak torque in different ankle joints (i.e., -10º, 0º, and 20º of plantar flexion - 0º neutral position).
Changes in Achilles tendon stiffness
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Tendon stiffness will be obtained by calculating the slope in the last 10% of the linear region of the force-deformation curve.
5 secondary outcomes
Changes in Achilles tendon Young's Modulus
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in Achilles tendon morphological properties
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in plantar flexors' muscle arquitecture
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in plantar flexors' muscle activation
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Changes in neuromuscular recruitment capacity
Time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Jan 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jeam M Geremia, PhD study director
Federal University of Rio Grande do Sul
Marcelo H Glänzel, MSc principal investigator
Federal University of Rio Grande do Sul
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Exercise in people with Achilles Tendon Rupture and Strength Training Adaptations, run by Federal University of Rio Grande do Sul at 1 site in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 30 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jeam M Geremia, PhD (+5505133085852, jeam.geremia@ufrgs.br), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in foot and ankle joint function (time frame: From baseline measurements up to 13 weeks after (i.e., one week after the end of the training program)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Jan 2026.