ARTICLE –
abstractThe
effects of ankle joint position and gastrocnemius muscle contraction
and relaxation on anterior tibial translation Jeff G. Konin1, Barbara
Melzer2, Leah Nof3,
Elizabeth Swann4, William Athans5 1Department
of Orthopedics & Sports Medicine University of South Florida,
College of Medicine Tampa, Florida 2Department
of Physical Therapy, Texas State University, San Marcos Texas 3Physical
Therapy Program Nova Southeastern University Fort Lauderdale, Florida 4Director,
Athletic Training Education Program Nova Southeastern University Fort
Lauderdale, Florida 5Research
Collaborator, Medical Student University of South Florida, College of
Medicine Tampa, Florida
Abstract
Historically,
anterior tibial translation of the tibia on the femur has been assessed
with clinical examinations tools both manual and mechanical that assure
hamstring muscle relaxation in an effort to measure true
movement. To date, no studies have reported similar outcomes
with
modified positions of the ankle joint or muscle contractile states of
the gastrocnemius muscle. Given the biomechanical and
anatomical
attachments of the two-joint gastrocnemius muscle, it was hypothesized
that altering the position and/or the muscle contractile state would
minimize the amount of anterior tibial translation. A
Quasi-experimental design with repeated measures.assessed the anterior
tibial translation of thirty male and thirty female intercollegiate
athletes in the United States between the ages of 18-23. Each subject
was examined for anterior tibial translation in one of four ankle joint
positions and the amount of anterior tibial translation in millimeters
was recorded. Results found altered ankle joint positions and
gastrocnemius muscle contractile states significantly decreased the
amount of anterior tibial translation of the tibiofemoral joint at the
α = 0.05 level when compared to the normal resting ankle
position. These findings suggest testing for anterior tibial
translation should occur with slight plantar flexion of the ankle in a
relaxed gastrocnemius muscle state, in an effort to prevent against
false negative assessments of movement. Furthermore, such findings may
have implications on rehabilitation exercises designed to decrease
anterior tibial translation shear forces.
Key
words:tibial
translation, rehabilitation, biomechanical
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