Article

Age at menarche impacts patterns of pubertal growth and skeletal
development. These effects may carry over into variation in biomechanical
profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal
walking. OBJECTIVE: To test the hypothesis that earlier menarche is related to
postpubertal biomechanical risk factors for knee injuries, including a wider,
more immature gait base of support, and greater valgus knee angles and moments.
DESIGN: Cross-sectional observational study. SETTING: University research
facility. PARTICIPANTS: Healthy, postmenarcheal, adolescent girls. METHODS: Age
at menarche was obtained by recall questionnaire. Pubertal growth and
anthropometric data were collected by using standard methods. Biomechanical data
were taken from tests of walking gait at self-selected speed. Reflective marker
position data were collected with a 3-dimensional quantitative motion analysis
system, and 3 force plates recorded kinetic data. MAIN OUTCOME MEASURES: Age at
menarche; growth and anthropometric measurements; base of support; static knee
frontal plane angle; and dynamic knee frontal plane angles and moments during
stance. RESULTS: Earlier menarche was correlated significantly with abbreviated
pubertal growth and postpubertal retention of immature traits, including a wider
base of support. Earlier menarche and wider base of support were both correlated
with more valgus static knee angles, more valgus knee abduction angles and
moments at foot-strike, and a more valgus peak knee abduction angle during
stance. Peak knee abduction moment during stance was not correlated with age at
menarche or base of support. CONCLUSIONS: Earlier menarche and its effects on
growth are associated with retention of a relatively immature gait base of
support and a tendency for static and dynamic valgus knee alignment. This
biomechanical profile may put girls with earlier menarche at greater risk for
sports-related knee injuries. LEVEL OF EVIDENCE: Not applicable.
CI - Copyright (c) 2017 American Academy of Physical Medicine and Rehabilitation.
Published by Elsevier Inc. All rights reserved.

Langue : ANGLAIS