Stretching to Improve Jumping Performance

Flexibility Training (Stretching) to Improve Jumping Performance

The study involves comparison of an 8-week plantar flexor stretching program to a shoulder stretching program for improving vertical jump performance in adolescent athletes.

Study Overview

• Status: Recruiting
• Conditions: Vertical Jump Performance
• Intervention / Treatment: Other: Stretching

Detailed Description

Increasing flexibility may improve vertical jump performance. For example, being able to go deeper into a squat before jumping may allow for greater force development through the range of movement and this may transfer to greater vertical jump height. The study compares plantar flexor stretching to shoulder stretching for improving vertical jump performance in adolescent athletes. Athletes are being stratified by sex and maturity status (before or after estimated age at peak height velocity) and randomized to one of two groups: Plantar flexor stretching (2 sets of 6 stretches, 5 times per week) or the same volume of shoulder stretching. Before and after training, participants are being assessed for vertical jump and landing performance.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Philip Chilibeck, PhD; Phone Number: 306-966-1072; Email: phil.chilibeck@usask.ca

Study Locations

• Canada
  • Saskatchewan
    • Saskatoon, Saskatchewan, Canada, S7K 2X2
      • Recruiting
      • College of Kinesiology University of Saskatchewan
      • Contact: Philip Chilibeck; Phone Number: 3062303849; Email: phil.chilibeck@usask.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Currently involved in a sport training program

Exclusion Criteria:

• Current or past injuries that might affect jumping performance or stretching the plantar flexors or shoulder joint

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Plantar flexor stretching; Flexibility training (stretching) of the muscles at the back of the lower leg	Other: Stretching; Stretching of the plantar flexors or the shoulder joint
Active Comparator: Shoulder stretching; Flexibility training (stretching) of the muscles surrounding the shoulder joint	Other: Stretching; Stretching of the plantar flexors or the shoulder joint

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Counter movement jump height	Counter movement jump height assessed on a force plate	Change over 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Take-off velocity	Take-off velocity assessed on a force plate in the right and left limbs	Change over 8 weeks
Ground reaction force on take off	Ground reaction force on take off from a counter movement jump on a force plate in right and left limbs	Change over 8 weeks
Ground reaction force on landing	Ground reaction force when landing from a jumping on force plate in right and left limbs	Change over 8 weeks
Ground reaction force when landing from a standard height	Ground reaction force when landing from a height (150% of baseline counter movement jump height)	Change over 8 weeks
Functional dorsiflexor range of movement	Functional dorsiflexor range of movement assessed with an inclinometer in left and right limbs	Change over 8 weeks
Active dorsiflexor range of movement	Active dorsiflexor range of movement assessed with a goniometer in right and left limbs	Change over 8 weeks
Passive dorsiflexor range of movement	Passive dorsiflexor range of movement assessed with a goniometer in right and left limbs	Change over 8 weeks
Shoulder flexibility	Shoulder flexibility assessed with a goniometer in right and left limbs	Change over 8 weeks

Collaborators and Investigators

• Sponsor: University of Saskatchewan

Study record dates

Study Major Dates

• Study Start (Actual): April 28, 2025
• Primary Completion (Estimated): April 28, 2026
• Study Completion (Estimated): May 30, 2026

Study Registration Dates

• First Submitted: April 17, 2025
• First Submitted That Met QC Criteria: April 17, 2025
• First Posted (Actual): April 25, 2025

Study Record Updates

• Last Update Posted (Actual): February 23, 2026
• Last Update Submitted That Met QC Criteria: February 19, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 4925

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No