Clinical trial NCT06924775: Jump Rope Training and Shoulder Isokinetics in CrossFit
Official title: Impact of Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners
Keywords: Isokinetic shoulder profile
Weighted jump rope training
Rotational peak torque
Muscle imbalance
Injury prevention
CrossFit
Lead sponsor: University of Americas
Sponsor class: OTHER
First posted: 2025-04-11
Enrollment: 18
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: SCREENING

Brief 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.

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

Eligibility criteria: Inclusion Criteria:

* 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.

Exclusion Criteria:

* 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.

Primary outcomes:
measure: Rotational peak torque relative to body mass
timeFrame: From enrollment to the end of wieghted jump rope training protocol at 6 weeks
Secondary outcomes:
Other outcomes:
Locations:
city: Viña del Mar
country: Chile
facility: Human Movement Analysis Laboratory
state: V región/Valparaíso
Study officials:
affiliation: University of Americas
name: Maximiliano A. Torres-Banduc, PhD.
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: Duzgun 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.