Thumbnail Image

Date

2024-08-02

Journal Title

Journal ISSN

Volume Title

Publisher

Pain is a widely experienced sensation that has been shown in previous research to decrease duration of exercise and maximal strength. PURPOSE: The purpose of this study was to determine if the application of knee pain impacts time-to-task failure and maximal strength measures. It also aimed to see if changing the location of knee pain between the ipsilateral (dominant) leg and the contralateral (non-dominant) impacted fatigue parameters, maximal strength differently and force recovery. METHODS: Participants (Females = 9, Males = 12, N/A = 1) completed five visits (2 familiarization and 3 experimental) separated by 48 hours. At the beginning of each of the visits, the electrical stimulus for participants to reach pain threshold and pain rated a 4/10 in the knee was obtained. The exercise protocol consisted of four pre-exercise MVCs (Maximal Voluntary Contractions), submaximal time-to-task failure protocol (intensity of 15% over critical torque), and 6-post exercise MVCs with the different conditions being contralateral knee pain, ipsilateral knee pain or no knee pain. RESULTS: The male participants had a higher MVC and twitch torque than the female participants (p<0.001) indicating males were stronger than women. Pre-exercise MVCs decreased significantly following application of knee pain, likely due to an increase in central fatigue (p<0.001). There was a main effect of time in force decrease (p<0.001), twitch torque (p<0.001), and % activation (p=0.005) during submaximal protocol. Regardless of pain condition, force output was fully recovered 240 seconds after exercise failure (p=0.067). Subjective pain measures of exercising muscle pain, regardless of condition, were increased at 60 seconds (p=0.030), immediately before failure (p=0.004), and immediately following exercise (p=0.007). When pain was applied to the ipsilateral knee, pain ratings decreased significantly over time, likely due to exercise induced hypoalgesia (p<0.001). Pain ratings in the ipsilateral knee were greater in the ipsilateral condition than they were in the control condition or the contralateral knee pain condition (p<0.001). When pain was applied to the contralateral knee, pain ratings were different over time also likely due to exercise induced hypoalgesia (p<0.001). Pain ratings in the contralateral knee were greater in the contralateral condition than they were in the control condition or the ipsilateral knee pain condition (p<0.001). CONCLUSIONS: The presence of knee pain regardless of location decreased MVCs and increased percent activation of the participants. Knee pain stimulus regardless of location did not impact time-to-task failure. Peripheral fatigue increased throughout the fatiguing exercise protocol. Maximal strength was recovered 240s after fatiguing exercise regardless of the presence and location of knee pain.

Description

Keywords

Fatigue, Pain, Maximum Force, Knee extensors, Force recovery

Citation

DOI

Related file

Notes

Collections