Stress fractures in the lower extremity result from excessive submaximal stress that is repeatedly placed on the region; this leads to accumulation of micro-damage in the region, disrupting bone homogeneity and causing fractures.
Commonly occurring in athletes, an early identification and management of stress fractures is essential to reduce the loss in significant training time and to facilitate a return to full activity.
Among the factors that can increase an individual’s predisposition to stress fractures, inherent biomechanical disparities or asymmetries necessitate a detailed understanding in order to protect the athlete and/or prevent recurrences.
While hyperpronation can increase torque forces acting on the foot, any inequality in leg length can place the lower limbs at a biomechanical disadvantageous position, promoting early degeneration of the hip joint and lumbar spine on the longer leg side.
As detailed by Joseph D’Amico, from the Division of Orthopaedics at the New York College of Podiatric Medicine, modifications in gait are prominent in those with a leg length discrepancy greater than 2 cm such as plantar flexion at the ankle with secondary Achilles contracture on the shorter limb.
In the case of discrepancies between 1 to 1.5 cm, the author describes the longer limb as being subjected to excessive ground reactive forces and isometric torque, which when coupled with repetitive movements in sports, can result in micro-fractures.
Timothy Miller and Christopher Kaeding, from the Department of Orthopaedics at The Ohio State University, state that leg length discrepancy has been reported by long distance runners as a major contributing factor to running injuries; with the longer leg more frequently associated with tibial, metatarsal and femur fractures.
This makes it necessary to address postural discrepancies that increase the risk of an individual developing stress fractures and to further provide protection from the onset of a number of lower extremity pathologies.
Functional leg length discrepancies caused by foot hyperpronation can be treated with a complete active rehabilitative programme inclusive of MASS4D® customised foot orthotics. Whilst structural leg length issues will benefit from the addition of a heel lift on the short leg side to balance the sacral base and rectify the compensatory scoliosis on the shorter side.
In addition to this, the use of customised foot orthotics such as MASS4D® should help reduce any excessive pressure on the site of injury by promoting an optimal distribution of plantar pressure and enforcing the optimal functioning of the foot and ankle complex.
Copyright 2018 MASS4D® All rights reserved.
Repetitive plantarflexion can lead to pain and mechanical limitation in the posterior ankle joint which is known as posterior ankle impingement syndrome. This pathology commonly occurs in ballet dancers and football players.