Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit PractitionersNCT06924775
Jump Rope Training and Shoulder Isokinetics in CrossFit
A study testing Weighted jump rope training in people with Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners, run by University of Americas - Chili at 1 site in Chile.
Trial summary
The goal of this quasi-experimental clinical trial is to evaluate whether weighted jump rope (WJR) training can improve the isokinetic shoulder strength profile in male and female CrossFit practitioners. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners
- What is being tested?
- Weighted jump rope training
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 18 participants
- Where
- 1 siteChile
- Study dates
- 30 Jul 2022to 30 Mar 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- self-reported CrossFit training experience. Accordingly, participants were classified into one of three categories (Torres-Banduc et al., 2021): advanced level (≥36 months of regular training, defined as ≥3 sessions of ≥120 minutes per week); intermediate level (12 to <36 months); and beginner level (6 to <12 months).
- no injuries in the three months preceding the study.
Who cannot join
- musculoskeletal issues impacting muscle strength or the ability to undergo isokinetic shoulder evaluation.
- self-reported use of anabolic steroids or other prohibited substances that might influence the study results.
Trial locations and contacts
1 site in 1 country.
Chile1 site
Human Movement Analysis Laboratory
Viña del Mar, V región/Valparaíso, 2340000
About this study
Official title: Impact of Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners
The goal of this quasi-experimental clinical trial is to evaluate whether weighted jump rope (WJR) training can improve the isokinetic shoulder strength profile in male and female CrossFit practitioners.
The main questions it aims to answer are:
Read more
- Does six weeks of WJR training affect internal and external shoulder rotational peak torque relative to body mass?
- Does WJR influence the external/internal shoulder rotation ratio in dominant and non-dominant arms at varying angular velocities? Researchers will compare pre- and post-intervention isokinetic measurements to see if WJR training leads to significant changes in shoulder strength and balance.
Participants will:
- Incorporate WJR sessions three times per week into their usual CrossFit training.
- Undergo isokinetic testing of both shoulders at baseline and post-intervention at 60°/s, 180°/s, and 300°/s.
- Have their training adherence and technique monitored throughout the study.
Read the detailed description
Model: Single Group
Model Description:
This study followed a single-arm, quasi-experimental pre-post design in which all participants underwent the same intervention: six weeks of weighted jump rope (WJR) training, integrated into their regular CrossFit routines. The intervention's impact on isokinetic shoulder strength variables was assessed by comparing pre- and post-intervention measures within the same group of participants.
Number of Arms
1, Only one group received the intervention-there was no control or comparator group.
Masking Outcomes Assessor.
Masking Description:
Due to the nature of the physical intervention (WJR training), blinding participants and care providers was not feasible. However, outcome assessors conducting the isokinetic tests were blinded to the study's hypotheses and group allocations to reduce measurement bias.
Allocation N/A. Participants were not randomly assigned but instead enrolled in a single group to undergo the same intervention protocol.
Enrollment 18 participants
- Being tested
- Weighted jump rope training
- Keywords
- Isokinetic shoulder profile, Weighted jump rope training, Rotational peak torque, Muscle imbalance, Injury prevention, CrossFit
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Weighted jump rope trainingOther
Unlike isolated jump rope studies, this intervention was embedded within the participants' habitual CrossFit routine, enhancing ecological validity. Performing the jump rope protocol immediately prior to regular training-rather than as a stand-alone session-was intended to promote warm-up and neuromuscular priming benefits. The use of a weighted rope introduced a resistance stimulus that is rarely incorporated in jump rope interventions.
| Study group | Role | What they receive |
|---|---|---|
| Weighted jump rope training group | Experimental | A progressive six-week jump rope protocol focusing on simple unders was completed three times per week, individually or in groups, before regular sessions. Training was supervised by final-year kinesiology students. Based on Duzgun et al. (2010), jumps increased weekly: Week 1-D1: 6×25, D2: 3×50, D3: 4×50 (500 total); Week 2-4×50, 4×75, 4×50 (750); Week 3-4×75, 4×75, 4×100 (1000); Week 4-6×75, 6×75, 5×70 (1250); Week 5-5×100, 4×150, 4×100 (1500); Week 6-5×150, 6×100, 4×100 (1750). Rest between sets: 1 min. Participants were advised to avoid prior intense activity, maintain steady pace, and received positive reinforcement as needed. Receives: Other: Weighted jump rope training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rotational peak torque relative to body mass
This variable represents the highest muscular force produced during a shoulder rotation movement, normalized to the participant's body mass (expressed in Nm/kg). It was measured using an isokinetic dynamometer, which quantifies muscle torque under controlled speed and resistance conditions. Participants performed maximal effort shoulder rotations to the left and right at a standardized angular velocity, with proper stabilization to isolate shoulder movement. Normalizing torque to body mass allows comparisons between individuals of different sizes and helps assess the relative strength of the shoulder rotator muscles. Higher values indicate greater rotational strength relative to body weight, which is important for upper limb performance and injury prevention.
Measured: From enrollment to the end of wieghted jump rope training protocol at 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Apr 2025
- Study start30 Jul 2022
- Primary completion30 Jan 2023
- Study completion30 Mar 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit PractitionersStudies 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
- Screening
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 18 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Americas - Chili
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Maximiliano Torres-Banduc, University of Americas - Chili
- Investigators
- Maximiliano A. Torres-Banduc, PhD., Principal investigator, University of Americas - Chili
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06924775
- Sponsor's protocol ID
- 23/2022
- Status last verified
- Apr 2025
- First submitted
- 4 Apr 2025
- Last updated
- 11 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Individual participant data will not be publicly shared, but may be made available upon reasonable request to the corresponding author. This approach ensures data privacy and confidentiality, while still allowing access for valid scientific purposes.
Publications
Torres-Banduc MA, Jerez-Mayorga D, Moran J, Keogh JWL, Ramirez-Campillo R. Isokinetic force-power profile of the shoulder joint in males participating in CrossFit training and competing at different levels. PeerJ. 2021 Sep 17;9:e11643. doi: 10.7717/peerj.11643. eCollection 2021.
PubMed 34616590Duzgun I, Baltaci G, Colakoglu F, Tunay VB, Ozer D. The effects of jump-rope training on shoulder isokinetic strength in adolescent volleyball players. J Sport Rehabil. 2010 May;19(2):184-99. doi: 10.1123/jsr.19.2.184.
PubMed 20543219Torres-Banduc MA, Thapa RK, Perez MA, Ramirez-Campillo R. Isokinetic shoulder strength adaptations to weighted jump rope training in CrossFit athletes: A pre-post study. Shoulder Elbow. 2025 Dec 30:17585732251409407. doi: 10.1177/17585732251409407. Online ahead of print.
PubMed 41479676
Study at a glance
From the registry record, last updated by the sponsor on 11 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners
- ClinicalTrials.gov ID
- NCT06924775
- Acronym / sponsor ID
- 23/2022
- Keywords
- Isokinetic shoulder profile, Weighted jump rope training, Rotational peak torque, Muscle imbalance, Injury prevention, CrossFit
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 18 participants (actual)
- Lead sponsor
- University of Americas - ChiliUniversity, hospital or other
- Study start
- 30 Jul 2022 (actual)
- Primary completion
- 30 Jan 2023 (actual)
- Study completion
- 30 Mar 2023 (actual)
- First posted
- 11 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.
The goal of this quasi-experimental clinical trial is to evaluate whether weighted jump rope (WJR) training can improve the isokinetic shoulder strength profile in male and female CrossFit practitioners.
The main questions it aims to answer are:
- Does six weeks of WJR training affect internal and external shoulder rotational peak torque relative to body mass?
- Does WJR influence the external/internal shoulder rotation ratio in dominant and non-dominant arms at varying angular velocities? Researchers will compare pre- and post-intervention isokinetic measurements to see if WJR training leads to significant changes in shoulder strength and balance.
Participants will:
- Incorporate WJR sessions three times per week into their usual CrossFit training.
- Undergo isokinetic testing of both shoulders at baseline and post-intervention at 60°/s, 180°/s, and 300°/s.
- Have their training adherence and technique monitored throughout the study.
Detailed description
Model: Single Group
Model Description:
This study followed a single-arm, quasi-experimental pre-post design in which all participants underwent the same intervention: six weeks of weighted jump rope (WJR) training, integrated into their regular CrossFit routines. The intervention's impact on isokinetic shoulder strength variables was assessed by comparing pre- and post-intervention measures within the same group of participants.
Number of Arms
1, Only one group received the intervention-there was no control or comparator group.
Masking Outcomes Assessor.
Masking Description:
Due to the nature of the physical intervention (WJR training), blinding participants and care providers was not feasible. However, outcome assessors conducting the isokinetic tests were blinded to the study's hypotheses and group allocations to reduce measurement bias.
Allocation N/A. Participants were not randomly assigned but instead enrolled in a single group to undergo the same intervention protocol.
Enrollment 18 participants
Study design
- Primary purpose
- Screening
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Weighted jump rope training group | Experimental | Other: Weighted jump rope trainingA progressive six-week jump rope protocol focusing on simple unders was completed three times per week, individually or in groups, before regular sessions. Training was supervised by final-year kinesiology students. Based on Duzgun et al. (2010), jumps increased weekly: Week 1-D1: 6×25, D2: 3×50, D3: 4×50 (500 total); Week 2-4×50, 4×75, 4×50 (750); Week 3-4×75, 4×75, 4×100 (1000); Week 4-6×75, 6×75, 5×70 (1250); Week 5-5×100, 4×150, 4×100 (1500); Week 6-5×150, 6×100, 4×100 (1750). Rest between sets: 1 min. Participants were advised to avoid prior intense activity, maintain steady pace, and received positive reinforcement as needed. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- self-reported CrossFit training experience. Accordingly, participants were classified into one of three categories (Torres-Banduc et al., 2021): advanced level (≥36 months of regular training, defined as ≥3 sessions of ≥120 minutes per week); intermediate level (12 to <36 months); and beginner level (6 to <12 months).
- no injuries in the three months preceding the study.
Key exclusion criteria (2 listed)
- musculoskeletal issues impacting muscle strength or the ability to undergo isokinetic shoulder evaluation.
- self-reported use of anabolic steroids or other prohibited substances that might influence the study results.
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 |
|---|---|---|
| Weighted jump rope trainingUnlike isolated jump rope studies, this intervention was embedded within the participants' habitual CrossFit routine, enhancing ecological validity. Performing the jump rope protocol immediately prior to regular training-rather than as a stand-alone session-was intended to promote warm-up and neuromuscular priming benefits. The use of a weighted rope introduced a resistance stimulus that is rarely incorporated in jump rope interventions. | Other | Weighted jump rope training group |
Primary outcome
Rotational peak torque relative to body mass
Time frame: From enrollment to the end of wieghted jump rope training protocol at 6 weeks
This variable represents the highest muscular force produced during a shoulder rotation movement, normalized to the participant's body mass (expressed in Nm/kg). It was measured using an isokinetic dynamometer, which quantifies muscle torque under controlled speed and resistance conditions. Participants performed maximal effort shoulder rotations to the left and right at a standardized angular velocity, with proper stabilization to isolate shoulder movement. Normalizing torque to body mass allows comparisons between individuals of different sizes and helps assess the relative strength of the shoulder rotator muscles. Higher values indicate greater rotational strength relative to body weight, which is important for upper limb performance and injury prevention.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Apr 2025.
- Background: PubMed 34616590Torres-Banduc MA, Jerez-Mayorga D, Moran J, Keogh JWL, Ramirez-Campillo R. Isokinetic force-power profile of the shoulder joint in males participating in CrossFit training and competing at different levels. PeerJ. 2021 Sep 17;9:e11643. doi: 10.7717/peerj.11643. eCollection 2021.
- Background: PubMed 20543219Duzgun I, Baltaci G, Colakoglu F, Tunay VB, Ozer D. The effects of jump-rope training on shoulder isokinetic strength in adolescent volleyball players. J Sport Rehabil. 2010 May;19(2):184-99. doi: 10.1123/jsr.19.2.184.
- Derived from this study: PubMed 41479676Torres-Banduc MA, Thapa RK, Perez MA, Ramirez-Campillo R. Isokinetic shoulder strength adaptations to weighted jump rope training in CrossFit athletes: A pre-post study. Shoulder Elbow. 2025 Dec 30:17585732251409407. doi: 10.1177/17585732251409407. Online ahead of print.
- Individual participant dataSharing planned: Undecided. Individual participant data will not be publicly shared, but may be made available upon reasonable request to the corresponding author. This approach ensures data privacy and confidentiality, while still allowing access for valid scientific purposes.
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. This study is not recruiting at the moment.
Maximiliano A. Torres-Banduc, PhD. principal investigator
University of Americas - Chili
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Weighted jump rope training in people with Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners, run by University of Americas - Chili at 1 site in Chile.
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 2 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: finished, as of the sponsor's last update on 11 Apr 2025. 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 Chile. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rotational peak torque relative to body mass (time frame: From enrollment to the end of wieghted jump rope training protocol at 6 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06924775, which also lists 3 linked publications.
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 11 Apr 2025.