Determining the Effect of Shoulder Flexion Angle on Latissimus Dorsi and Forearm Flexor Hypertrophy

NCT07360236 | Not Yet Recruiting

• 1 other identifier: H25-03685
• Study Type: interventional
• Target: 20
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this clinical trial is to learn the effect of training a muscle at a longer or shorter muscle length during resistance exercise in young and healthy adults. Participants will undergo two types of resistance training conditions that are randomly assigned to the left and right arm. The LATPULLDOWN (LPD) condition refers to performing an exercise that places the latissimus dorsi muscle at a long muscle length when the shoulder is elevated to 180° of shoulder flexion. The LATROW (LR) condition refers to performing an exercise that places the latissimus dorsi muscle at a shorter muscle length when the shoulder is elevated to 90° of shoulder flexion. The main questions the trial aims to answer are:

• Resistance train the left and right arm with two separate conditions; LAT PULLDOWN and LAT ROW for 12 weeks, with the first and last weeks dedicated to only strength testing (Isotonic and Isokinetic) and measuring muscle volume via magnetic resonance imaging (MRI)
• Visit the gym for resistance training 2 times per week
• Visit the UBC MRI Research Facility in weeks 1 and 12 for MRI of muscle volume

Conditions

Muscle Hypertrophy; Muscular Strength

Keywords

Muscle hypertrophy; Long muscle length; Short muscle length; Range of motion; Muscular strength; 1RM; Length-tension Relationship; Resistance Training; Neuromechanical Matching; Latissimus dorsi; Lat Pulldown; Lat Row

Outcome Measures

Primary Outcomes (1)

• Muscle volume and Cross sectional area

  Muscle volume of the latissimus dorsi, biceps brachii, brachialis, posterior deltoid and teres major muscle will be measured by cross sectional area (CSA) via Magnetic Resonance Imaging (MRI). The entire muscle length will be imaged and images at 25%, 50% and 75% of the entire muscle length will be analyzed to calculate CSA and any regional differences in hypertrophy.

  From enrolment to the end of the intervention at 12 weeks

Secondary Outcomes (2)

• Isotonic strength testing (1RM)

  Initial testing in week 1 and final testing in week 12

• Isokinetic strength testing

  Initial testing in week 1 to final testing in week 12

Study Arms (1)

LAT PULLDOWN and LAT ROW Training Protocol

EXPERIMENTAL

Using a within subject design, participants will have the arms from both left and right side of the body (divided by sagittal plane) randomly assigned to either LAT PULLDOWN or LAT ROW conditions. Participants will then engage in maximal strength testing on the Lat Pulldown and Lat Row cable machines (1RM) as well as isokinetic strength testing (1080 Quantum Syncro) in weeks 1 and 12. Participants will engage in the LAT PULLDOWN and LAT ROW training sessions for 10 weeks in duration from week 2 until week 11.

Other: LAT PULLDOWN and LAT ROW training sessions; Other: Maximal isotonic strength testing (1RM); Other: Isokinetic strength testing (1080 Quantum)

Interventions

LAT PULLDOWN and LAT ROW training sessions OTHER

One arm will be randomly assigned to perform LAT PULLDOWN and the contralateral arm will be randomly assigned to perform LAT ROW on a cable machine. Each exercise will include 1 warm up set at 50% 1RM followed by 4-5 sets of 8-12 repetitions per limb. 2 minutes of rest between sets on the ipsilateral limb with 30s between the contralateral limb. The left and right limbs will alternate each session in which one starts each exercise, resulting in 10 training sessions each where the left and right limbs starts first on each exercise. All sets will be performed to momentary failure. A Dynamic Double Progression will be employed to ensure intensity is maintained throughout the intervention.

LAT PULLDOWN and LAT ROW Training Protocol

Maximal isotonic strength testing (1RM) OTHER

Each limb will perform a 1RM strength test of the Lat Pulldown and Lat Row on the cable machine respectively. Testing will occur in weeks 1 and 12 of the study with the non-dominant arm tested before the dominant arm. Participants self-selects first warm up set with a weight that is performed between 6-10 repetitions on both limbs. Rest for 1 minute between limbs and subsequent set. A weight is then selected by research staff to perform 3 repetitions with based on previous set. Load is now increased until 1RM is achieved. 3 minutes of rest will be taken between 1RM attempts, with 1RM being complete within 3-5 attempts. Participant will rest 3 minutes before starting testing on the other exercise. The 1RM protocol is repeated for the second exercise. Initial strength testing results and progression from the 10 week training intervention will help to inform testing weights for the post strength testing session. Post strength testing will follow the same protocol as pre strength testing.

LAT PULLDOWN and LAT ROW Training Protocol

Isokinetic strength testing (1080 Quantum) OTHER

Participants will engage in isokinetic strength testing on the 1080 Quantum Syncro machine in weeks 1 and 12 for both movements: Shoulder extension from 180° and shoulder extension from 90°. Participants will perform each movement unilaterally. Participants will start with the non-dominant arm. Each movement will be tested through A maximal active range of motion. Participants will complete 10 sub-maximal repetitions to allow familiarization each movement. After a 2-minute rest, participants will complete 4 maximal concentric and eccentric repetitions with 3 minutes rest at 30°/second for 3 sets. The protocol is then repeated on the dominant limb.

LAT PULLDOWN and LAT ROW Training Protocol

Eligibility Criteria

• Age: 19 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Any sex
• Able to understand and communicate in English
• years of age
• All "No" answers on the CSEP Get Active questionnaire or doctors' approval to participate
• Trained participants: Structured resistance training over at least the past 12-months (i.e., ≥ 2 hours per week of structured/periodized training)

You may not qualify if:

• Participants will be excluded from this study if they meet any of the following criteria:
• BMI lower than 18 or greater than 30
• Difficulty to understand and communicate in English
• Current use of cigarettes or other nicotine devices
• Any major uncontrolled cardiovascular, muscular, metabolic, and/or neurological disorders
• Any medical condition impacting the ability to participate in maximal exercise
• Type one or type two diabetes
• Diagnosis of cancer or undergoing cancer treatment in the past 12 months
• Drug therapy with any drugs that alter skeletal muscle metabolism (i.e., Metformin, Benzodiazepines)
• Implants containing ferrous metal
• Surgery or tattoos (including tattooed eyeliner) in the last 6 weeks
• Pregnancy
• CANNOT participate if you have any of the following:
• Retained wires from an electronic implant that has been removed (i.e., pacemaker wires not attached to a pacemaker)
• Cardiac pacemaker or defibrillator

Sponsors & Collaborators

• University of British Columbia: lead

Study Officials

• Cameron J Mitchell, PhD

  The University of British Columbia, School of Kinesiology

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Adam G Jones, B.Kin, MSc Kinesiology Student

CONTACT

12365135196; adamgj@student.ubc.ca

Dr. Cameron Mitchell

CONTACT

6048272702; cameron.mitchell@ubc.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: The MRi analyst will be blinded to the the unique participant code assigned to each MRi file when measuring cross sectional area and muscle volume. Another member of the research group will assign random numbers to each copy of the MRi files that are measured by the MRi analyst.
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Within-Subject Design: Each participant will have the left and right arm randomly assigned to the either LAT PULLDOWN or LAT ROW condition. Each participant will perform both conditions, exclusively for the left or right arm. This helps to control for genetics, nutrition, recovery, stress management and training history as each participant acts as a self-control group as well as both experimental conditions.

Study Record Dates

• First Submitted: January 14, 2026
• First Posted: January 22, 2026
• Study Start: January 15, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: January 22, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share