The effect of leg length discrepancy on spinal motion during gait: three-dimensional analysis in healthy volunteers.
METHODS
This study focused on the effects of leg length discrepancy on the motion of the normal spine during gait in healthy male volunteers who wore a heel-raising orthotic device on the right foot.


OBJECTIVE
To evaluate the effect of leg length discrepancy on the changes in curvature of the normal spine during gait.


BACKGROUND
There are few published data on the effects of leg length discrepancy on the motion of the normal spine during gait.


METHODS
An orthotic device that raised the heel by 3 cm was used to simulate leg length discrepancy. Twenty-two healthy male volunteers participated (age: 28.2 +/- 6.1 years, average +/- SD). The dynamic curvatures of the spine under two conditions (without and with a heel-raising orthotic device; normal gait and heel-raising gait) were evaluated during gait. The leg length discrepancy values without and with the device were measured and analyzed using a VICON system (Oxford Metrics, United Kingdom).


RESULTS
The spine showed an asymmetrical lateral-bending motion during heel-raising gait as compensation for the leg length discrepancy. Maximum lateral bending angle of the thoracic spine was 4.2 +/- 1.4 degrees in heel-raising gait, whereas it was 3.0 +/- 1.0 degrees in normal gait. Maximum lateral bending angle of the lumbar spine was 8.1 +/- 2.8 degrees in heel-raising gait, whereas it was 6.1 +/- 2.1 degrees in normal gait. The maximum bending angle and bending velocity were significantly larger in the heel-raising gait than in normal gait.


CONCLUSIONS
Patients who have leg length discrepancy due to disorders in the lower extremities are at greater risk of developing disabling spinal disorders due to exaggerated degenerative change. Therefore, treatment for leg length discrepancy may be helpful in preventing degenerative spinal changes.
Kakushima
Mototaka
M
Departments of Orthopaedic Surgery, Hirano General Hospital, Gifu, Japan.
Miyamoto
Kei
K
Shimizu
Katsuji
K
D000328:Adult; D001696:Biomechanical Phenomena; D005684:Gait; D006801:Humans; D021621:Imaging, Three-Dimensional; D007866:Leg / Q000033:anatomy & histology*; D007870:Leg Length Inequality / Q000150:complications; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009068:Movement; D009989:Orthotic Devices; D010388:Pelvis; D012782:Shoulder; D013122:Spinal Diseases / Q000209:etiology; D013131:Spine / Q000502:physiology*; D013904:Thoracic Vertebrae / Q000502:physiology