Biomechanical effect of altered lumbar lordosis on intervertebral lumbar joints during the golf swing: a simulation study.

Although the lumbar spine region is the most common site of injury in golfers, little research has been done on intervertebral loads in relation to the anatomical-morphological differences in the region. This study aimed to examine the biomechanical effects of anatomical-morphological differences in the lumbar lordosis on the lumbar spinal joints during a golf swing. The golf swing motions of ten professional golfers were analyzed. Using a subject-specific 3D musculoskeletal system model, inverse dynamic analyses were performed to compare the intervertebral load, the load on the lumbar spine, and the load in each swing phase. In the intervertebral load, the value was the highest at the L5-S1 and gradually decreased toward the T12. In each lumbar spine model, the load value was the greatest on the kypholordosis (KPL) followed by normal lordosis (NRL), hypolordosis (HPL), and excessive lordosis (EXL) before the impact phase. However, results after the follow-through (FT) phase were shown in reverse order. Finally, the load in each swing phase was greatest during the FT phase in all the lumbar spine models. The findings can be utilized in the training and rehabilitation of golfers to help reduce the risk of injury by considering individual anatomical-morphological characteristics.

The effect of a task-specific locomotor training strategy on gait stability in patients with cerebellar disease: a feasibility study.

PURPOSE: There is a lack of evidence-based recommendations for the physiotherapeutic intervention specifically for locomotor training in patients with cerebellar ataxia. The purpose of this study is to determine the feasibility and effect of a more specific rehabilitation strategy that aims to improve gait quality in patients with cerebellar ataxia. METHODS: Nineteen patients with degenerative cerebellar ataxia were recruited to participate in the study. The patients participated in a 12-week locomotor training program, two times per week for 1.5 h per session (a total of 24 training sessions). The treatment approach emphasized the relearning of proper gait movement strategies through intensive practice that enhances the patient's perception and control of the essential components of normal gait movement. RESULTS: A quantitative analysis of step-by-step gait performance indicated that postural sway during locomotion was reduced, and the gait movement pattern became more consistent after the 12-week locomotor training program. These improvements in gait stability persisted over the 3-month period following intervention. CONCLUSION: This study provides preliminary evidence that learning-based rehabilitation strategies targeting disease-specific locomotion symptoms may be helpful for reducing ataxic gait and improving motor control during walking in patients with cerebellar dysfunction. Implications for rehabilitation Physiotherapeutic interventions that aim to promote gait stability in cerebellar patients need to create a specific learning context that improve disease-related gait deficits. It is desirable to use explicit instructions to facilitate the conscious awareness and control of body center and posture. As patients reacquire the fundamental gait ability, providing training experience with various locomotor tasks that facilitate the transfer of learning may be helpful to increase generalizability of locomotor intervention.

An Optimal Cure Process to Minimize Residual Void and Optical Birefringence for a LED Silicone Encapsulant.

Silicone resin has recently attracted great attention as a high-power Light Emitting Diode (LED) encapsulant material due to its good thermal stability and optical properties. In general, the abrupt curing reaction of the silicone resin for the LED encapsulant during the curing process induces reduction in the mechanical and optical properties of the LED product due to the generation of residual void and moisture, birefringence, and residual stress in the final formation. In order to prevent such an abrupt curing reaction, the reduction of residual void and birefringence of the silicone resin was observed through experimentation by introducing the multi-step cure processes, while the residual stress was calculated by conducting finite element analysis that coupled the heat of cure reaction and cure shrinkage. The results of experiment and analysis showed that it was during the three-step curing process that the residual void, birefringence, and residual stress reduced the most in similar tendency. Through such experimentation and finite element analysis, the study was able to confirm that the optimization of the LED encapsulant packaging process was possible.