Acute effects of muscle fatigue on the knee joint-position sense of trained and non-trained individuals

• Author(s): Azevedo, Joana ; Rodrigues, Sandra ; Moreira-Silva, Isabel ; Cardoso, Ricardo ; Seixas, Adérito
• Date: 2024
• Origin: Athena Health & Research Journal
• Document Type: Journal article
• Language: English

Description

Background: The acute effects of muscle fatigue on the knee joint-position sense (KJPS) are not consensual. Although it is known that peripheral fatigue affects the muscle spindle function by increasing its discharge threshold, reports of positive and negative impacts of muscle fatigue on the KJPS of both trained and non-trained individuals can be found in the literature. Aim: To assess the acute effects of muscle fatigue on the KJPS of trained and non-trained individuals. Methodology: This quasi-experimental study consisted in a sample of 60 participants, 29 semi-professional soccer players and 31 non-trained individuals. KJPS of both groups was tested in the dominant and non-dominant limb in a seated position, before and immediately after a repetitive sit-to-stand fatigue task. Target ranges of 20º and 45º of knee flexion were used, describing an active repositioning method, and using an inertial measurement unit system. Absolute and relative angular errors were calculated. Results: After fatigue, a significant increase was seen regarding the absolute (p=0.034) and relative (p=0.017) angular errors only in the non-trained individuals during the 45º repositioning of the dominant limb. Conclusions: Muscle fatigue did not affect knee proprioceptive acuity of the soccer players, but decreased the KJPS of the non-trained individuals. Muscle fatigue seems to mainly affect the muscle mechanoreceptors of the dominant limb. Key-Words: Muscle Fatigue; Knee; Joint Position Sense; Proprioception