Abstract
The purpose of this study was to examine the influence of a history of low back pain
(LBP) on pelvic and lumbar kinematics during baseball hitting. Twenty collegiate male
baseball players (age, 21±1 years; height, 172.8±4.7 cm; weight, 72.7±6.2 kg; baseball
experience, 13±1 years) performed 5 bat swings. Participants were categorized into
the LBP group (n=10) or control group (n=10) based on having experienced lumbar spine
pain due to bat swing that lasted more than 24 h within the last 12 months. Three-dimensional
kinematic data of the pelvis and lumbar spine during bat swing were measured. Two-way
ANOVAs were used to compare pelvic and lumbar kinematics throughout the bat swing
between groups, and independent t-tests were used to compare the other outcomes between
groups. There was a significant main effect between groups in lumbar flexion angle
throughout the bat swing (p=0.047). The mean lumbar flexion angle of the LBP group
throughout the bat swing was less than that of the control group. Additionally, the
peak angular velocity of lumbar flexion of the LBP group was significantly faster
than that of control group (p=0.047). These results can be helpful for longitudinal
studies that identify the risk factors of LBP due to bat swing.
Key words
bat swing - kinematics - 3D motion analysis - lumbar spine