Knee Joint Laxity and Its Cyclic Variation Influence Tibiofemoral Motion during Weight Acceptance

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Beverly Levine (Creator)
David H. Perrin, Former Provost and Executive Vice Chancellor (Creator)
Randy J. Schmitz, Associate Professor (Creator)
Sandra J. Shultz, Professor and Chair (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Purpose - To better understand how sex differences in anterior knee joint laxity (AKL) impact knee joint biomechanics, we examined the consequence of greater absolute baseline (males and females) and cyclic increases in AKL during the menstrual cycle (females) on anterior tibial translation (ATT) as the knee transitioned from non-weight bearing (NWB) to weight bearing (WB) conditions, while also controlling for genu recurvatum (GR). Methods - Males and females (71F,48M;18-30 years) were measured for AKL and GR, and underwent measurement of ATT. Females were tested on the days of their cycle when AKL was at its minimum (T1) and maximum (T2); males were matched in time to a female with similar AKL. Linear regressions examined relationships between absolute baseline (AKLT1, GRT1) and cyclic changes (?=T2-T1; AKL?, GR?)(females only) in knee laxity with ATT as measured at T1 and T2, and ? (T2-T1) (females only). Results - AKL and GR increased in females, but not males, from T1 to T2. Greater AKLT1 and GRT1 predicted greater ATTT1 and ATTT2 in males (R2=21.0, P<.007). The combination of greater AKLT1, AKL? and less GR? predicted greater ATTT1 and ATTT2 in females (R2=12.5-13.1, P<.05), with AKL? being a stronger predictor (coefficient, P-value) of ATTT2 (0.864, P=.027) compared to ATTT1 (0.333, P=.370). AKL? was the sole predictor of ATT? (R2=.104; 0.740, P=.042). Conclusions - Greater absolute baseline and cyclic increases in AKL were consistently associated with greater ATT produced by transition of the knee from NWB to WB. As the ACL is the primary restraint to ATT, these findings provide insight into possible mechanisms by which greater AKL may be associated with at risk knee biomechanics during the weight acceptance phase of dynamic tasks.

Additional Information

Publication
Medicine and Science in Sports Exercise, 43(2), 287-295
Language: English
Date: 2011
Keywords
injury mechanisms, anterior knee laxity, genu recurvatum, knee biomechanics, hormone response, menstrual cycle

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