An interventional study of LLLT and Sham in Muscle Fatigue Caused by Repetitive Muscle Exercise, sponsored by Chia Nan University of Pharmacy ＆ Science. Completed at 1 site in Taiwan. Open to male participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Chia Nan University of Pharmacy ＆ Science · Not applicable, Interventional, and Basic science
This randomized, sham-controlled, two-period crossover study evaluated the effects of portable 808-nm low-level laser therapy (LLLT) on acute recovery and running biomechanics following a quadriceps-dominant fatiguing task in recreational runners. Twenty male recreational runners completed both active LLLT and sham conditions, separated by a 2-week washout period. After the fatiguing task, participants received 10 minutes of bilateral quadriceps LLLT or sham treatment, followed by treadmill running at the same fixed self-selected speed. Quadriceps soreness, heart rate, running spatiotemporal parameters, and kinematic responses were assessed using a verbal numerical rating scale, heart-rate monitoring, two-dimensional video analysis, and inertial measurement units.
Each participant completed two experimental visits in randomized order, with one active LLLT condition and one sham condition separated by a 2-week washout period. At each visit, participants completed a 5-minute treadmill warm-up followed by a 3-minute pre-fatigue running trial at a fixed self-selected running speed. They then performed a repeated stand-sit-stand task designed to produce quadriceps-dominant lower-limb fatigue.
Immediately after the fatiguing task, participants received either active portable 808-nm LLLT or sham treatment for 10 minutes over the bilateral rectus femoris, vastus lateralis, and vastus medialis muscles. A 3-minute post-intervention treadmill running trial was then performed at the same running speed used before the fatiguing task.
Quadriceps soreness was assessed using a 0-10 verbal numerical rating scale. Heart rate was monitored using a chest-strap heart-rate monitor. Running spatiotemporal and kinematic variables were assessed using high-frame-rate two-dimensional video analysis and three inertial measurement units positioned over the bilateral distal tibiae and sacral region.
2,229 studies on the registry are indexed under Fatigue; 426 are open to participants now.
This study's enrollment of 20 is below the median of 54 across 1,757 interventional studies indexed under Fatigue.
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Exclusion Criteria:
Participants received LLLT during the first experimental period and sham during the second experimental period, with a 2-week washout period between visits.
Device: LLLT · Device: Sham
Participants received sham during the first experimental period and LLLT during the second experimental period, with a 2-week washout period between visits.
Device: LLLT · Device: Sham
Portable 808-nm low-level laser therapy applied bilaterally to the rectus femoris, vastus lateralis, and vastus medialis for 10 minutes.
Sham device applied to the same bilateral quadriceps sites for 10 minutes, matching the LLLT condition in device appearance, placement, duration, and fixation.
Quadriceps Soreness
Quadriceps soreness was assessed using a 0-10 verbal numerical rating scale (VNRS), where 0 indicated no soreness and 10 indicated the worst imaginable soreness. Decimal responses were permitted.
Time frame: Immediately after the 10-minute intervention and before the post-intervention running trial.
Distal-Tibial Acceleration at Initial Contact
Resultant distal-tibial acceleration was measured using bilateral inertial measurement units and expressed in meters per second squared (m/s²). Values from 10 consecutive steps were averaged for each limb, and the left- and right-limb means were subsequently averaged.
Time frame: At initial contact during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Distal-Tibial Angular Velocity at Initial Contact
Resultant distal-tibial angular velocity was measured using bilateral inertial measurement units and expressed in degrees per second (°/s). Values from 10 consecutive steps were averaged for each limb, and the left- and right-limb means were subsequently averaged.
Time frame: At initial contact during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Distal-Tibial Angular Velocity at Toe-Off
Resultant distal-tibial angular velocity was measured using bilateral inertial measurement units and expressed in degrees per second (°/s). Values from 10 consecutive steps were averaged for each limb, and the left- and right-limb means were subsequently averaged.
Time frame: At toe-off during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Distal-Tibial Acceleration at Toe-Off
Resultant distal-tibial acceleration was measured using bilateral inertial measurement units and expressed in meters per second squared (m/s²). Values from 10 consecutive steps were averaged for each limb, and the left- and right-limb means were subsequently averaged.
Time frame: At toe-off during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Step Width During Running
Step width was measured from posterior-view two-dimensional video analysis and expressed in centimeters. Ten consecutive steps were analyzed and averaged for each participant and condition.
Time frame: During the 3-minute post-intervention treadmill running trial; 10 consecutive steps were analyzed from 60 to 120 seconds after the start of running.
Sacral Acceleration at Initial Contact
Resultant sacral acceleration was measured using an inertial measurement unit positioned over the S2 region and expressed in meters per second squared (m/s²). Values from 10 consecutive steps were averaged for each participant and condition.
Time frame: At initial contact during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Sacral Acceleration at Toe-Off
Resultant sacral acceleration was measured using an inertial measurement unit positioned over the S2 region and expressed in meters per second squared (m/s²). Values from 10 consecutive steps were averaged for each participant and condition.
Time frame: At toe-off during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Sacral Angular Velocity at Initial Contact
Resultant sacral angular velocity was measured using an inertial measurement unit positioned over the S2 region and expressed in degrees per second (°/s). Values from 10 consecutive steps were averaged for each participant and condition.
Time frame: At initial contact during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Sacral Angular Velocity at Toe-Off
Resultant sacral angular velocity was measured using an inertial measurement unit positioned over the S2 region and expressed in degrees per second (°/s). Values from 10 consecutive steps were averaged for each participant and condition.
Time frame: At toe-off during the post-intervention treadmill running trial; events were identified within the 60-120-second analysis interval.
Heart Rate at the End of the Intervention
Heart rate was recorded using a Polar H10 chest-strap heart-rate monitor and averaged over the final 10 seconds of the 10-minute intervention. Heart rate was expressed in beats per minute (beats/min).
Time frame: During the final 10 seconds of the 10-minute intervention.
Sagittal Trunk Inclination Angle at Initial Contact
Sagittal trunk inclination angle was measured from lateral-view two-dimensional video analysis and expressed in degrees. Positive values indicated trunk flexion and negative values indicated trunk extension. Ten consecutive steps were analyzed and averaged for each participant and condition.
Time frame: At initial contact during the post-intervention treadmill running trial; 10 consecutive steps were analyzed from 60 to 120 seconds after the start of running.
Sagittal Trunk Inclination Angle at Toe-Off
Sagittal trunk inclination angle was measured from lateral-view two-dimensional video analysis and expressed in degrees. Positive values indicated trunk flexion and negative values indicated trunk extension. Ten consecutive steps were analyzed and averaged for each participant and condition.
Time frame: At toe-off during the post-intervention treadmill running trial; 10 consecutive steps were analyzed from 60 to 120 seconds after the start of running.
Knee-Flexion Angle at Initial Contact
Knee-flexion angle was measured from lateral-view two-dimensional video analysis and expressed in degrees. Smaller values represented a more extended knee position. Ten consecutive steps were analyzed and averaged for each participant and condition.
Time frame: At initial contact during the post-intervention treadmill running trial; 10 consecutive steps were analyzed from 60 to 120 seconds after the start of running.
Knee-Flexion Angle at Toe-Off
Knee-flexion angle was measured from lateral-view two-dimensional video analysis and expressed in degrees. Smaller values represented a more extended knee position. Ten consecutive steps were analyzed and averaged for each participant and condition.
Time frame: At toe-off during the post-intervention treadmill running trial; 10 consecutive steps were analyzed from 60 to 120 seconds after the start of running.
Plan to share: No — Individual participant data will not be made publicly available because of participant privacy and ethical considerations. De-identified data may be available from the corresponding author upon reasonable request, subject to applicable ethical and institutional restrictions.
Ran from Feb 2025 to primary completion in Jun 2025, 4 months.
Of 936 non-industry interventional studies with no phase under Fatigue, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 27. This study's 4 months is below that.
Counting every sponsor, half of 989 studies reached it within 11 months; a quarter within 5 and three quarters within 27.
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This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Chia Nan University of Pharmacy ＆ Science