A study of 26 healthy and seven male patients with lower back disc herniation (LDH) investigated the kinematic effects of LDH on the multi-segmental spine, pelvis, and lower extremities during activities of daily living (ADL). The intent of the study was to help establish a clearer understanding of how LDH affects the movement of the spinal segments and to assist in the future development of more effective rehabilitation regimens for patients suffering from LDH.
The study 1 used 3D active markers strategically-placed at the thorax, pelvis, hip, knee, ULx, and LLx to track the motion of spinal segments during five pre-determined ADLs. The subjects were monitored during three rounds of level walking, stair climbing, trunk flexion, ipsilateral pickup, and contralateral pickup, and the data was collected and calculated using the AnyBody managed model repository (AMMR, version 1.6 and version 6.0.6) systems. Computer models then analyzed kinematic angles, and the range of motion (ROM) was calculated for joint or segmental angles in three planes during flexion-extension or gait cycles. A custom program was created and utilized in MATLAB (The MathWorks, Inc) and each of the variables and stats were compared to independent studies involving control groups.
Subjects with LDH demonstrated statistically greater pelvic and LLx rotation during stair-climbing than subjects in the control group. The LDH patients also had a reduced ROM during thoracic flexion, and had more hip abduction, and greater degrees of pelvic tilt during the activities. There was a slight difference in thoracic flexion ROM between the control and LDH groups, but the LDH group had a significantly decreased ROM in lumbar flexion, particularly in ULx without sagittal angular displacement. When performing ipsilateral or contralateral pickups, the LDH group compensated the lack of lumbar flexion with a tilted pelvis. The LDH patients had increased ROM during trunk flexion in pelvic rotation the frontal and transverse planes. During ipsilateral pickup, they demonstrated greater pelvic rotation and hip abduction, but decreased ROM of LLx when bending laterally during trunk flexion.
The study indicates that patients will alter their kinetics to avoid pain from LDH. These adaptive strategies during ADLs occurred in the thoracic, ULx, LLx, pelvis, and right-side lower extremities, indicating different compensations in the two segments of the lumbar region. The lumbar region during the five ADLs utilized a small amount of intersegmental movement, and the LDH patients demonstrated less pelvic rotation during stair climbing and contralateral pickup, but more during other ADLs. As mentioned, fear of pain may be responsible for a greater pelvic rotation in LDH patients during activities.
This study of kinetic characteristics and range of motion and direction in subjects with, and without LHD should contribute to increased understanding of how LDH influences spinal movement and will hopefully lead to enhanced rehabilitation techniques in the clinical treatment of LDH. Further research of the kinetics of the lower extremities, pelvis, spinal segments in reaction to LDH might include an investigation of the inverse dynamics of loads, particularly at the disc, facet joint, hip, pelvis, knee, and ankle. An examination of the ligament and muscular forces involved during kinetic adjustment could also benefit clinicians.