Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Aug;45(8):1553-61.
doi: 10.1249/MSS.0b013e31828cb94e.

Multiplanar knee laxity increases during a 90-min intermittent exercise protocol

Sandra J Shultz  1 , Randy J Schmitz, John R Cone, Timothy J Copple, Melissa M Montgomery, Michele L Pye, Amanda J Tritsch
Affiliations

Multiplanar knee laxity increases during a 90-min intermittent exercise protocol

Sandra J Shultz et al. Med Sci Sports Exerc. 2013 Aug.

Abstract

Purpose: This study aimed to examine changes in sagittal (AP LAX), frontal (VV LAX), and transverse (IER LAX) plane knee laxity in men and women during an intermittent exercise protocol (IEP) simulating the intensity and duration of a soccer match.

Methods: Intercollegiate/club athletes (29 females and 30 males) were measured on AP LAX (-90 to 130 N) before and after warm-up and every 15 min during and for 1 h after the IEP. VV LAX (± 10 N · m) and IER LAX (± 5 N · m) were measured before and after warm-up, at the end of each 45-min half, and at 30 min after exercise. Values were compared to a control (no exercise) condition.

Results: Compared to control condition, females increased AP LAX and VV LAX during the IEP, whereas males did not (P < 0.037). AP LAX increased within 15 min of exercise (9.5 ± 2.1 mm), and peak values obtained at the end of the first (10.1 ± 2.0 mm) and second half (10.1 ± 2.1 mm) were 12% greater than before warm-up values (9.0 ± 1.8 mm). VV LAX increased before warm-up (9.5° ± 3.4°) to the end of each half (both 10.4° ± 3.2°; 10% increase) and remained elevated 30 min after exercise (10.5° ± 2.9°). Both sexes increased IER LAX from before warm-up (25.5° ± 6.1°) to all time points (after warm-up = 26.6° ± 6.0°, first half = 27.0° ± 6.6°, second half = 27.3° ± 6.5°, 30 min after exercise = 26.95° ± 5.7°; P = 0.007). Changes in AP LAX (-0.10 to 5.9 mm), VV LAX (-1.7° to 5.7°), and IER LAX (-4.1° to 13.3°) during exercise varied considerably among individuals in both sexes, with a larger proportion of females experiencing substantial changes in AP LAX and VV LAX.

Conclusions: Although exercise-related knee laxity changes were more pronounced in females, there was a subset of both males and females who experienced substantial knee laxity increases during exercise. Whether these individuals are more susceptible to higher-risk lower extremity biomechanics and injury risk later in a game or practice is currently under investigation.

PubMed Disclaimer

Publication types