THE EFFECT OF SHOE WEIGHT ON GROUND REACTION FORCES IN INDIVIDUALS WITH AN ACL INJURY DURING DROP LANDING

Anterior cruciate ligament accounts for 80% of all knee ligament surgeries. The
purpose of this study was to investigate the effect of shoe weight on ground reaction forces in individuals
with an ACL injury during drop landing.
Materials & Methods: The present study was semi-experimental and laboratory. Statistical samples
included 10 men with an ACL injury and 10 healthy men who volunteered to participate in this study.
Reaction force data during a single drop landing were collected from a step with a height of 30 cm by
Bertec force plate device. Both groups used shoes under four conditions: 1. Shoe weight, 2. Shoe weight
and increase of 100 grams, 3. Shoe weight and increase of 200 grams and 4. Shoe weight and increase
of 300 grams. Five correct attempts were recorded with different shoe weights. A two-way analysis of
variance test was used for statistical comparison.
Results: Based on the findings of this study, there was a significant difference in the peak of internalexternal
force (p = 0.008; d = 1.420), anterior-posterior impulse (p = 0.011; d = 1.328), Vertical impulse
(p = 0.024; d = 1.164), and positive free moment (p = 0.057; d = 0.492) between the healthy group and
ACL injury during single drop landing. Also, there was a significant difference in the peak of anteriorposterior
force (p = 0.002; d = 1.136), time to the peak of internal-external power (p = 0.005; d = 1.034),
the time to peak vertical force (p = 0.011; d = 0.950), and vertical loading rate (p = 0.062; d = 0.759) in
single drop landing.
Conclusion: Overall, increasing the weight of shoes in healthy people and the ACL group increases the
pressure on the joint and the injury. The use of lightweight shoes is recommended as a minimum of
prevention to reduce ACL injury