File
Bangerter C1,2, Romkes J3, Lorenzetti S4,5, Krieg A6, Hasler C-C6, Brunner R3,6, Schmid S1,4
1Bern University of Applied Sciences, Department of Health Professions, Bern, Switzerland, 2Physio Hildebrandt, Bern, Switzerland, 3University of Basel Children's Hospital, Laboratory for Movement Analysis, Basel, Switzerland, 4ETH Zurich, Institute for Biomechanics, Zurich, Switzerland, 5Swiss Federal Institute of Sport Magglingen SFISM, Magglingen, Switzerland, 6University of Basel Children's Hospital, Orthopedic Department, Basel, Switzerland
Background: Structural leg length discrepancy (LLD) is a common phenomenon. The most frequent treatment for LLD is the use of orthotic shoe lifts. Recent studies have stated an association between LLD and lower back pain, lumbar disc herniation or osteoarthritis of the spine. However, evidence on spinal gait kinematics and the immediate effect of an orthotic shoe lift in patients with a structural LLD are still lacking.
Purpose: Previous studies assessing the effect of LLD on gait either focused on changes in lower extremities, only investigated participants with artificially induced LLD, or used inadequate methods to quantify spinal kinematics. Assessing the effect of a structural LLD on spinal kinematics can provide useful information to clinicians, but may also contribute more precise insights to investigations of treatment effects (orthotic devices or surgical interventions). This study therefore aims at investigating spinal gait kinematics in patients with structural LLD and at evaluating the immediate effect of an orthotic shoe lift.
Methods: Participants comprised 10 adolescents with structural LLD (20-60 mm) and 14 healthy controls. All of whom were fitted with a combination of the full body Plug-in Gait and a specific trunk marker set. Subsequently participants were requested to walk barefoot as well as with an orthotic shoe lift (only patients). Data were collected using a 12-camera Vicon motion capture system and spinal angles were calculated in MATLAB using a circle fit function. Outcomes included spinal and pelvic angles in all three planes, lower extremity joint angles as well as spatiotemporal gait parameters. Group comparisons were conducted using one-dimensional Statistical Parametric Mapping (SPM). Differences were only considered clinically relevant if they were greater than 5°.
Results: Patients with LLD showed statistically significant and clinically relevant larger frontal plane lumbar bending angles to the longer side during early stance (p=0.007, 0-21% of gait cycle [%GC]) and terminal swing phase (p=0.009, 82-100%GC), increased pelvic tilt to the shorter side (p 0.001, 0-100%GC) and larger hip adduction angles on the longer leg (p 0.001, 0-100%GC) for the entire gait cycle compared to healthy controls. In the sagittal plane, patients demonstrated increased knee extension on the shorter side in the mid-stance phase (p=0.014, 48-51%GC) and more dorsiflexion in the ankle joint of the longer side in the terminal stance phase (p=0.002, 53-66%GC). Moreover, all gait deviations observed in patients with LLD could immediately be influenced by correcting the LLD using a shoe lift.
Conclusion(s): As a reaction to LLD, patients showed a lateral pelvic tilt towards the shorter side, which appeared to be compensated by lateral bending of the lumbar spine. Contrary to previous studies on healthy subjects, LLD patients did not show counter-compensation in the thoracic spine but a lateral shift of the pelvis towards the longer side. Using orthotic corrections seems to be a suitable option to instantly normalize gait kinematics in this population.
Implications: This study contributes to a better understanding of both secondary gait deviations seen in patients with structural LLD and the immediate effect of an orthotic correction on spinal, pelvic and lower extremity kinematics.
Keywords: Gait analysis, Biomechanics, Trunk movement
Funding acknowledgements:
1. Department of Health Professions at Bern University of Applied Sciences
2. Swiss Physiotherapy Association
Purpose: Previous studies assessing the effect of LLD on gait either focused on changes in lower extremities, only investigated participants with artificially induced LLD, or used inadequate methods to quantify spinal kinematics. Assessing the effect of a structural LLD on spinal kinematics can provide useful information to clinicians, but may also contribute more precise insights to investigations of treatment effects (orthotic devices or surgical interventions). This study therefore aims at investigating spinal gait kinematics in patients with structural LLD and at evaluating the immediate effect of an orthotic shoe lift.
Methods: Participants comprised 10 adolescents with structural LLD (20-60 mm) and 14 healthy controls. All of whom were fitted with a combination of the full body Plug-in Gait and a specific trunk marker set. Subsequently participants were requested to walk barefoot as well as with an orthotic shoe lift (only patients). Data were collected using a 12-camera Vicon motion capture system and spinal angles were calculated in MATLAB using a circle fit function. Outcomes included spinal and pelvic angles in all three planes, lower extremity joint angles as well as spatiotemporal gait parameters. Group comparisons were conducted using one-dimensional Statistical Parametric Mapping (SPM). Differences were only considered clinically relevant if they were greater than 5°.
Results: Patients with LLD showed statistically significant and clinically relevant larger frontal plane lumbar bending angles to the longer side during early stance (p=0.007, 0-21% of gait cycle [%GC]) and terminal swing phase (p=0.009, 82-100%GC), increased pelvic tilt to the shorter side (p 0.001, 0-100%GC) and larger hip adduction angles on the longer leg (p 0.001, 0-100%GC) for the entire gait cycle compared to healthy controls. In the sagittal plane, patients demonstrated increased knee extension on the shorter side in the mid-stance phase (p=0.014, 48-51%GC) and more dorsiflexion in the ankle joint of the longer side in the terminal stance phase (p=0.002, 53-66%GC). Moreover, all gait deviations observed in patients with LLD could immediately be influenced by correcting the LLD using a shoe lift.
Conclusion(s): As a reaction to LLD, patients showed a lateral pelvic tilt towards the shorter side, which appeared to be compensated by lateral bending of the lumbar spine. Contrary to previous studies on healthy subjects, LLD patients did not show counter-compensation in the thoracic spine but a lateral shift of the pelvis towards the longer side. Using orthotic corrections seems to be a suitable option to instantly normalize gait kinematics in this population.
Implications: This study contributes to a better understanding of both secondary gait deviations seen in patients with structural LLD and the immediate effect of an orthotic correction on spinal, pelvic and lower extremity kinematics.
Keywords: Gait analysis, Biomechanics, Trunk movement
Funding acknowledgements:
1. Department of Health Professions at Bern University of Applied Sciences
2. Swiss Physiotherapy Association
Topic: Musculoskeletal: spine
Ethics approval required: Yes
Institution: University of Basel Children's Hospital
Ethics committee: Ethikkommission Nordwest- und Zentralschweiz
Ethics number: 33/13
All authors, affiliations and abstracts have been published as submitted.
