Upper extremity motion during gait in adolescents with structural leg length discrepancy - An exploratory study.

Background and purpose
Depending on the extent of a structural leg length discrepancy (LLD), several compensatory mechanisms take place in order to maintain function and to optimize energy consumption during gait. However, studies describing the influence of a structural LLD on upper limb motion are lacking. The current study therefore aimed at the evaluation of upper limb motion during gait in LLD patients compared to healthy controls.

Methods
Motion capture data from 14 patients with structural LLD and 15 healthy controls that were collected during barefoot walking at a self-selected speed were retrospectively analyzed. Specifically, kinematic parameters of the shoulder and elbow joints as well as the trunk segment were investigated and considered in relation to a minimal clinically important difference of 5°.

Results
The shoulders in LLD patients were kept constantly in a more extended and at initial contact in a more adducted position as compared to healthy controls. In addition, the patients’ elbow joints showed increased flexion motion and the trunk segment indicated a constant trunk lateral-flexion and axial rotation tendency towards the affected side.

Conclusions
Patients with structural LLD indicated clinically relevant secondary deviations in shoulder and elbow motion. While some of these deviations were most likely passive physical effects, others might have occurred as active strategies to maintain balance or to regulate total body angular momentum. These findings contribute to the understanding of secondary gait deviations induced by a structural LLD and might serve as a basis for further investigations using complex musculoskeletal models.