Influence of Whole Body Vibration on Drop Jump Landings and Knee Loading Mechanics
Plyometric training is one commonly used method of improving jump performance through improving explosive power generation. Research has also demonstrated that whole body vibration (WBV) can improve jumping and enhance explosive strength especially when supplementing resistance and plyometric training programs. With the drop jump being a common training skill, proper lower extremity landing mechanics are important to consider. Limited evidence suggests that WBV may reduce ground reaction forces and improve knee stability however, its influence on knee loading have not been reported. This study sought to examine the effects of WBV on ground reaction forces and knee valgus during a drop jump. 19 participants (10 female) completed drop jumps pre, immediately post, 10 & 20 minutes post WBV. Results were analyzed by repeated measures ANOVA. Main findings indicated that valgus knee angle increased significantly (p=0.011) post vibration and remained elevated across the 10 & 20 minute post vibration time intervals. Significant differences between sexes revealed that females demonstrated greater internal knee abduction moments (p=0.038). Findings that WBV increases knee valgus angle, a position linked to anterior cruciate ligament injury, suggest further investigation understand the effects of WBV on neuromuscular control and eccentric loading. Strength and conditioning professionals should exercise caution when incorporating WBV into plyometric protocols.DOI: 10.29245/2767-5130/2021/1.1152 View / Download Pdf
The Impact of Lumbar Spine Disease on Hip-Spine Relationship in Total Hip Arthroplasty: A Mini-Review
Background: Patients with severe lumbar spine diseases run a high risk of dislocation after total hip arthroplasty. Therefore, it is essential to determine the pathological effect of common lumbar diseases on pelvic motions before the surgery.
Aim: This study reviewed the literature on the hip-spine relationship during total hip arthroplasty and explored the degenerative presentations and management of four common lumbar disorders. The review showed that patients with the spinal deformity in ankylosing spondylitis (AS) were characterized by thoracolumbar kyphosis with corresponding hip extension and pelvic retroversion, prone to anterior hip dislocation; patients with lumbar spinal fusion (LSF) were more susceptible to prosthetic impingement and ultimate dislocation, especially in the limited posterior tilt of the pelvis while sitting; those with degenerative disc disease (DDD) had a greater compensatory pelvic posterior angle while standing and greater hip joint flexion while sitting to compensate for the reduced lumbar flexion; those with degenerative lumbar spondylolisthesis (DSPL) demonstrated a pelvic flexibility with a much wider range and relative acetabular anteversion, especially when standing.
Recommendation: According to the literature, spinal osteotomy and total hip arthroplasty are the most common surgical interventions in AS cases. DSPL is classified into the Flexible & Unbalanced type and should be placed more posteriorly, but the literature suggests that patients with lumbar instability should first be placed in a more predictable position. In contrast, LSF and DDD are categorized as the Rigid & Balanced type. For these two types of disorders, the literature suggests that acetabular prostheses require more anterior tilt at the time of implantation.
Conclusion: These findings indicate that for degenerative lumbar disorders, a balance between stable component implantation and minimal wear should be based on the different changes in spinopelvic mobility.DOI: 10.29245/2767-5130/2022/1.1151 View / Download Pdf
No-touch smartphone technique to confirm acetabular cup position in Total Hip Replacement
In order to achieve good results following Total hip replacement , proper and reproducible acetabular cup placement is of paramount importance. The safe zone described by Lewwinick is still considered to be the target cup position. Various techniques have been used to improve the precision and accuracy of cup placement including the use of computer navigation which is often prohibitively expensive for developing countries. We present a ‘No touch smartphone technique’ to check positioning of acetabular cup intra operatively, without compromising the sterility of the operative field which we have found to be simple, quick, inexpensive and reproducible.DOI: 10.29245/2767-5130/2022/1.1156 View / Download Pdf