Affiliations: [a] Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA | [b] College of Health Sciences, University of Kentucky, Lexington, KY, USA | [c] Department of Health and Physical Activity, School of Education, University of Pittsburgh, Pittsburgh, PA, USA | [d] Michael W. Krzyzewski Human Performance Laboratory (K-Lab), Department of Orthopaedic Surgery, School of Medicine, Duke University, Durham, NC, USA
Correspondence:
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Corresponding author: Katelyn F. Allison, Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water Street, Pittsburgh, PA 15203, USA. Tel.: +1 412 246 0460; Fax: +1 412 246 0461; E-mail:kaf14@pitt.edu
Abstract: BACKGROUND: Fatiguing exercise may impair functional joint
stability and increase injury risk. Musculoskeletal and physiological
characteristics are related to fatigue, but their relationship with
proprioceptive changes following fatigue is unknown. OBJECTIVE: To establish the relationship between strength and
physiological characteristics and changes in knee proprioception following
fatigue. METHODS: Physically active women (N = 20, 28.7 ± 5.6 years,
165.6 ± 4.3 cm, 61.8 ± 8.0 kg) underwent isokinetic knee strength and
peak oxygen uptake (VO2peak)/lactate threshold (LT) testing during Visit 1,
and threshold to detect passive motion (TTDPM) and isometric knee strength
testing before and after fatiguing exercise during Visit 2. RESULTS: Fatigue demonstrated no effect on TTDPM despite a decrease
in isometric knee flexion strength (P< 0.05). Strength and physiological
variables were not significantly correlated with changes in TTDPM. VO2peak
was correlated with pre-fatigue (r= -0.50) and post-fatigue (r= -0.52) TTDPM
into extension (P< 0.05), and further analyses demonstrated that post-fatigue
changes in isometric knee flexion strength and strength ratio were related
to post-fatigue changes in proprioception (r= -0.62 and -0.40, P< 0.05). CONCLUSIONS: Physically active women with higher aerobic capacity
exhibit enhanced knee proprioception, and may benefit from training to
strengthen and reduce the fatigability of the knee flexors following intense
exercise, as these changes were associated with reduced proprioception.
