The goal of this clinical trial is to learn if chiropractic ankle manipulation can improve squat jump performance. It will also learn about the relationship among chiropractic ankle manipulation, ankle range of motion, and squat jump performance. The main questions it aims to answer are: * Does chiropractic ankle manipulation increase squat jump height? * Is there a relationship among chiropractic ankle manipulation, ankle range of motion, and squat jump performance? Researchers will compare squat jump performance between subjects who receive chiropractic ankle manipulations with control subjects to see if ankle chiropractic manipulation works to improve squat jump performance. Participants will: * Visit the research laboratory for one testing session to measure ankle range of motion and squat jump performance, before and after their randomly assigned intervention arm * Receive either a chiropractic ankle manipulations or rest quietly as the control condition during the testing session.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
60
The lower extremity manipulation (LEM) procedure is a short lever, high velocity, low-amplitude distractive (caudal) thrust directed at the talocrural joint. The treating chiropractor will deliver the LEM to the right ankle then the left ankle. LEM is an adjustment for long axis distraction of the tibiotalar joint with the goal to improve dorsiflexion of the ankle joint.
Biomechanics Laboratory at Northeast College of Health Sciences
Seneca Falls, New York, United States
Squat Jump Height
Subjects will be instructed to jump upwards from the starting squat position as high as possible. Subjects will perform 3 to 6 jumps with 3 consecutive jump heights being within 5% of each other to ensure maximum jump height is achieved. There will be a one-minute rest between jumps. * Starting position. Subjects will assume the starting squat position with their hips at 90°, knees at 120°, and ankles at 85° as positioned by the PI. An adjustable plyometric jump box will be used to standardize the starting position. Hands will be resting across their chest with the trunk and head positioned straight ahead. * Squat Jump: Subjects will be instructed to jump as high as possible and land in a comfortable position. Hands will remain across the chest for the duration of The Optojump photoelectric cell system (OptoJump) will be used to record jump height. OptoJump demonstrates strong concurrent validity and excellent test-retest reliability for the estimation of vertical jump height
Time frame: Baseline on Day 1 to Immediately after Intervention on Day 1
Range of Motion of Ankle Dorsiflexion
Knee-to-wall ankle dorsiflexion test: * Ankle dorsiflexion ROM (distance from wall - cm) is the maximum distance of the big toe from the wall while maintaining contact between the wall and the knee with the heel on the ground. * The subject will repeat the Knee-to-wall ankle dorsiflexion test three times at this maximum distance to allow the PI to record three goniometer measurements of ankle dorsiflexion ROM (degrees°).
Time frame: Baseline on Day 1 to Immediately after Treatment on Day 1 and at End of Test Session on Day 1
Leg Muscle Power (W/Kg)
Squat Jump Muscle Parameter: The Optojump will calculate an estimate of leg muscle power (W/Kg). The reliability and concurrent validity of OptoJump to measure jump height suggests that the evidence-base biomechanical formula to calculate the estimate of leg muscle power by OptoJump is reliable with face validity.
Time frame: Baseline on Day 1 to Immediately after Intervention on Day 1
Contraction Velocity of Leg Muscles (mm/s), Force-Velocity Curve
Squat Jump Muscle Parameter: The Gyko inertial sensor system (Gyko) will measure the velocity of the jump to calculate an estimate of the contraction velocity of leg muscles, force-velocity curve. The reliability and concurrent validity of Gyko to measure jump height and in-turn estimate muscle function parameters is limited in the literature. The control group in the current study will allow us to address concurrent validity and reliability of Gyko to measure jump height. Jump height measured by Optojump is the gold-standard field base device. Comparison of Gyko to Optojump measurements of jump heights will determine concurrent validity of Gyko to estimate jump height. The use of evidence-base biomechanical formulas to calculate an estimate of contraction velocity of leg muscles during SQJ's depends on recording reliable and valid measurements of jump heights; and in turn, establish the reliability and face validity of Gyko to estimate muscle function parameters.
Time frame: Baseline on Day 1 to Immediately after Intervention on Day 1
Rate of Force Development of Leg Muscles (N/s), Slope of the Force - Velocity Curve
Squat Jump Muscle Parameter: The Gyko inertial sensor system (Gyko) will measure the velocity of the jump to calculate an estimate of the rate of force development of leg muscles, slope of the force - velocity curve The reliability and concurrent validity of Gyko to measure jump height and in-turn estimate muscle function parameters is limited in the literature. The control group in the current study will allow us to address concurrent validity and reliability of Gyko to measure jump height. Jump height measured by Optojump is the gold-standard field base device. Comparison of Gyko to Optojump measurements of jump heights will determine concurrent validity of Gyko to estimate jump height. The use of evidence-base biomechanical formulas to calculate an estimate of the rate of force development of leg muscles during SQJ's depends on recording reliable and valid measurements of jump heights; and in turn, establish the reliability and face validity of Gyko to estimate muscle function.
Time frame: Baseline on Day 1 to Immediately after Intervention on Day 1
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