|
Woman and ACL Injury
Researchers in the American Journal of Sports Medicine
say that variations of the menstrual cycle and the use of an
oral contraceptive do not affect knee or hip joint loading
during jumping and landing tasks...injury rates is more likely
attributable to persistent differences in strength,
neuromuscular coordination, or ligament properties.
Chaudhari AM, Lindenfeld TN,
Andriacchi TP, Hewett TE, Riccobene J, Myer GD, Noyes FR.
Knee and Hip Loading Patterns at Different Phases in the
Menstrual Cycle: Implications for the Gender Difference in
Anterior Cruciate Ligament Injury Rates.Am J Sports Med.
2007 Feb 16
BACKGROUND: Menstrual cycle phase has been correlated with risk
of noncontact anterior cruciate ligament injury in women. The
mechanism by which hormonal cycling may affect injury rate is
unknown.
HYPOTHESES: Jumping and landing activities performed during
different phases of the menstrual cycle lead to differences in
foot strike knee flexion, as well as peak knee and hip loads, in
women not taking an oral contraceptive but not in women taking
an oral contraceptive. Women will experience greater normalized
joint loads than men during these activities.
STUDY DESIGN: Controlled laboratory study.
METHODS: Twenty-five women (13 using oral contraceptives) and 12
men performed repeated trials of a horizontal jump, vertical
jump, and drop from a 30-cm box on the left leg. Lower limb
kinematics (foot strike knee flexion) and peak externally
applied moments were calculated (hip adduction moment, hip
internal rotation moment, knee flexion moment, knee abduction
moment). Men were tested once. Women were tested twice for each
phase of the menstrual cycle (follicular, luteal, ovulatory), as
determined from serum analysis. An analysis of variance was used
to examine differences between phases of the menstrual cycle and
between groups (alpha = .05). RESULTS: No significant
differences in moments or knee angle were observed between
phases in either female group or between the 2 female groups or
between either female group and the male controls.
CONCLUSIONS: Variations of the menstrual cycle and the use of
an oral contraceptive do not affect knee or hip joint loading
during jumping and landing tasks.
CLINICAL RELEVANCE: Because knee and hip joint loading is
unaffected by cyclic variations in hormone levels, the observed
difference in injury rates is more likely attributable to
persistent differences in strength, neuromuscular coordination,
or ligament properties.
|
