Lower extremity energy absorption and biomechanics during landing, part II: frontal-plane energy analyses and interplanar relationships.
BACKGROUND
Greater sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing is consistent with sagittal-plane biomechanics that likely increase anterior cruciate ligament (ACL) loading, but it does not appear to influence frontal-plane biomechanics. We do not know whether frontal-plane INI EA is related to high-risk frontal-plane biomechanics.


OBJECTIVE
To compare biomechanics among INI EA groups, determine if women are represented more in the high group, and evaluate interplanar INI EA relationships.


METHODS
Descriptive laboratory study.


METHODS
Research laboratory.


METHODS
Participants included 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active volunteers.


METHODS
We assessed landing biomechanics with an electromagnetic motion-capture system and force plate.


METHODS
We calculated frontal- and sagittal-plane total, hip, knee, and ankle INI EA. Total frontal-plane INI EA was used to create high, moderate, and low tertiles. Frontal-plane knee and hip kinematics, peak vertical and posterior ground reaction forces, and peak internal knee-varus moment (pKVM) were identified and compared across groups using 1-way analyses of variance. We used a χ (2) analysis to evaluate male and female allocation to INI EA groups. We used simple, bivariate Pearson product moment correlations to assess interplanar INI EA relationships.


RESULTS
The high-INI EA group exhibited greater knee valgus at ground contact, hip adduction at pKVM, and peak hip adduction than the low-INI EA group (P < .05) and greater peak knee valgus, pKVM, and knee valgus at pKVM than the moderate- (P < .05) and low- (P < .05) INI EA groups. Women were more likely than men to be in the high-INI EA group (χ(2) = 4.909, P = .03). Sagittal-plane knee and frontal-plane hip INI EA (r = 0.301, P = .006) and sagittal-plane and frontal-plane ankle INI EA were associated (r = 0.224, P = .04). No other interplanar INI EA relationships were found (P > .05).


CONCLUSIONS
Greater frontal-plane INI EA was associated with less favorable frontal-plane biomechanics that likely result in greater ACL loading. Women were more likely than men to use greater frontal-plane INI EA. The magnitudes of sagittal- and frontal-plane INI EA were largely independent.
College of Public Health and Human Sciences, Oregon State University, Corvallis.
Marc F
MF
Norcross
Michael D
MD
Lewek
Darin A
DA
Padua
Sandra J
SJ
Shultz
Paul S
PS
Weinhold
J Troy
JT
Blackburn
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena / Q000502:physiology*; D001842:Bone and Bones / Q000502:physiology; D004735:Energy Transfer / Q000502:physiology*; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D007718:Knee Injuries; D007719:Knee Joint / Q000502:physiology*; D007866:Leg / Q000502:physiology*; D008297:Male; D011187:Posture / Q000502:physiology; D012737:Sex Factors; D033081:Shear Strength / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology; D055815:Young Adult