Table 2.
Biomechanical Factors |
Exercise-Related Increases in APLAX and SPTIME |
Exercise-Related Increases in VVLAX and IERLAX |
||||||||
Slopesb |
Interceptc |
Baseline Knee Laxityd |
Slopese |
Interceptc |
Baseline Knee Laxityd |
|||||
AP, mmd |
VV, °d |
IER, °d |
AP, mmd |
VV, °d |
IER, °d |
|||||
1: Greater hip-flexion motion and energy absorption | SPTIME | −0.60f | VVLAX | |||||||
APLAX | −0.02 | −0.03f | IERLAX | |||||||
2: Greater initial hip-flexion and hip-extensor loading | SPTIME | −0.55f | VVLAX | |||||||
APLAX | 0.04 | −0.01f | IERLAX | −0.03 | 0.01f | |||||
3: Greater knee and ankle flexion and knee energy absorption | SPTIME | −0.55 | 0.68f | −0.10f | VVLAX | 0.52f | 0.07g | |||
APLAX | −0.08 | −0.14g | IERLAX | −0.02 | 0.02g | |||||
4: Greater knee-extensor loading | SPTIME | −0.32f | 0.44f | −0.45f | −0.04f | VVLAX | −0.19 | −0.03f | ||
APLAX | 0.23g | 0.02g | IERLAX | −0.01 | 0.06f | −0.08f | 0.01f | |||
5: Greater initial ankle dorsiflexion with less excursion | SPTIME | 0.39f | 0.07f | VVLAX | 0.36g | |||||
APLAX | −0.08 | −0.03g | IERLAX | |||||||
6: Greater ankle plantar-flexor loading and knee shear forces | SPTIME | −0.41f | VVLAX | |||||||
APLAX | IERLAX | |||||||||
7: Began and remained in greater hip external rotation, knee valgus, and knee internal rotation | SPTIME | −0.51f | VVLAX | |||||||
APLAX | IERLAX | −0.05 | −0.04g | 0.05g | ||||||
8: Greater pure frontal-plane knee-valgus motion | SPTIME | VVLAX | 0.34f | 0.24f | ||||||
APLAX | IERLAX | 0.05f | 0.01f | |||||||
9: Greater knee internal-rotation motion during landing | SPTIME | VVLAX | ||||||||
APLAX | 0.19f | 0.12g | 0.02g | IERLAX | ||||||
10: Greater knee external-rotation motion during landing | SPTIME | 0.61f | 0.79g | VVLAX | ||||||
APLAX | IERLAX | 0.05 | −0.04g | 0.01g | ||||||
11: Less frontal- and transverse-plane hip and knee loading | SPTIME | VVLAX | −0.16 | 0.29g | ||||||
APLAX | IERLAX |
Abbreviations: AP, anterior-posterior; APLAX, anterior-posterior knee laxity; IER, internal-external rotation; IERLAX, internal-external rotation knee laxity; SPTIME, sprint time; VV, varus-valgus; VVLAX, varus-valgus knee laxity.
The nonsignificant findings that are not included in this Table can be found in Supplemental Tables 1 and 2 (available online at http://dx.doi.org/10.4085/1062-6050-49.5.08.S2).
SPTIME and APLAX slopes describe the extent to which exercise-related changes in SPTIME and APLAX, respectively, predict exercise-related changes in each biomechanical factor within a person.
The intercept represents the average expected change in the factor score for every unit change in the predictor variable (ie, 1-second change in SPTIME, 1-mm change in APLAX, and 1° change in VVLAX and IERLAX).
The baseline laxity coefficients represent the extent to which an individual's initial knee-laxity measures (APLAX, VVLAX, and IERLAX at pre-warm-up) moderate the relationship (or slope) between the independent variable (eg, SPTIME) and the factor score. Specifically, for an individual with a baseline knee-laxity value that is 1 unit value above or below the group mean, the average expected change (ie, slope of the intercept) is predicted to increase or decrease, respectively, by that amount.
The VVLAX and IERLAX slopes describe the extent to which exercise-related changes in VVLAX and IERLAX, respectively, predict additional exercise-related changes in each biomechanical factor that was not previously explained by SPTIME and APLAX.
Indicates coefficient (slope) is different from zero (P < .05).
Indicates coefficient (slope) is different from zero (P < .10).