Sports activity participation after curved periacetabular osteotomy for acetabular dysplasia.

BACKGROUND: Curved periacetabular osteotomy (CPO) was developed to treat acetabular dysplasia. Given that CPO can improve physical function in the early post-operative period, patients might be able to participate in sports activities post-operatively. Therefore, this study examined the post-operative sports activity participation and characteristics of acetabular dysplasia patients who have undergone CPO. METHODS: A total of 52 patients who underwent CPO for acetabular dysplasia were given a questionnaire on pre- and post-operative sports activities; 43 patients responded. We surveyed patients' sports activities, satisfaction, and physical function. Patients were divided according to whether they participated in sports activities after CPO. Physical function was compared before and after CPO. RESULTS: The pre- and post-operative sports activity participation rates were 55.8 and 72.1%, respectively. Patients mostly performed low-impact sports activities. Moreover, patients who participated in sports activities post-operatively had smaller pre-operative range of motion of hip flexion and returned to full weight bearing earlier. CONCLUSIONS: Among acetabular dysplasia patients who underwent CPO, 72.1% participated in sports activities post-operatively. Post-operatively, patients participated not only in low-impact sports activities, but also in high-impact ones. These findings might be useful for advising patients who are concerned about participating in sports activities after CPO.

Effects of Tissue Flossing and Dynamic Stretching on Hamstring Muscles Function.

Tissue flossing aims to improve range of motion (ROM), reduce pain, and enhance injury prevention. However, evidence is lacking regarding its effects. Therefore, this study examined the effects of flossing on hamstring muscles function in comparison to dynamic stretching (DS). Seventeen healthy young men ([mean ± SD] age, 23.2 ± 1.1 years; height, 1.72 ± 0.08 m; body mass, 63.5 ± 9.3 kg) volunteered as subjects in this randomized crossover trial. The subjects received flossing, DS, and control interventions in random order at least 1 week apart to eliminate the influence of the previous intervention. Flossing involved passive twisting and active movement using a floss band (Sanctband COMPRE Floss Blueberry, Sanct Japan Co., Ltd.). DS was performed for 4 minutes in 30-second sets consisting of 15 repetitions of 2 seconds stretching. The following were measured before and after each intervention: straight leg raise (SLR) test, passive knee extension (KE) test, passive torque, passive stiffness, fascicle length in the biceps femoris long head as an indication of hamstring muscles flexibility, and maximal isometric knee flexion contraction, maximal eccentric knee extension/flexion contraction, rate of force development, and muscle activity. Flossing yielded significant improvements in the SLR test (mean difference in post-intervention changes between interventions: 5.4°, percentage change from pre- to post-value: 13.4%, p = 0.004), passive KE test (6.2°, 4.5%, p < 0.001), passive torque at end-ROM (3.8 Nm, 4.7%, p = 0.03), and maximal eccentric knee flexion contraction (14.9% body weight, 8.2%, p = 0.03) than control. Moreover, flossing yielded 2.1-fold greater improvements in the passive KE test (3.8°, 4.5%, p = 0.03) and yielded significant improvements in the maximal eccentric knee extension contraction (29.9% body weight, 13.8%, p = 0.02) than DS. Therefore, flossing on hamstring muscles is more beneficial than DS with respect to increasing ROM and muscle exertion.

Effect of Devised Simultaneous Physical Function Improvement Training and Posture Learning Exercises on Posture.

Poor posture in young adults and middle-aged people is associated with neck and back pain which are among the leading causes of disability worldwide. Training posture maintenance muscles and learning about ideal posture are important for improving poor posture. However, the effect of using both approaches simultaneously has not been verified, and it is unclear how long the effects persist after the intervention. Forty female university students were randomly and evenly assigned to four groups: physical function improvement training, posture learning, combination, and control groups. Four weeks of intervention training was conducted. Postural alignment parameters were obtained, including trunk anteroposterior inclination, pelvic anteroposterior inclination, and vertebral kyphosis angle. Physical function improvement training for improving crossed syndrome included two types of exercises: "wall-side squatting" and "wall-side stretching". The posture learning intervention consisted of two types of interventions: "standing upright with their back against the wall" and "rolled towel". A multiple comparison test was performed after analysis of covariance to evaluate the effect of each group's postural change intervention on postural alignment. Only the combination group showed an effective improvement in all posture alignments. However, it was found that a week after the 4-week intervention, the subjects' postures returned to their original state.

Simulation of thrombus formation in shear flows using Lattice Boltzmann Method.

This article describes the prediction of index of thrombus formation in shear blood flow by computational fluid dynamics with the Lattice Boltzmann Method (LBM), applying to backward-facing step flow, which is a simple model of shear flow in the rotary blood pumps and complicated geometry of medical fluid devices. Assuming that the blood flow is a multiphase flow composed of blood plasma and activated fibrinogen, the effects of surface tension and adhesion force to the wall were added to the LBM computational model. It was found that the thrombus formation in the backward-facing step flow occurred just after the reattachment point and behind the step. These results corresponded to our observation results of thrombus formation. For the thrombus formation in every case of blood flow to be predicted, effects of threshold level of physical parameters such as shear rate and adhesion force (effective distance from the wall) were estimated. Moreover, it was also found that the predicted adhesion point on the wall agrees with the visualization of thrombus formation by predicting proper thresholds.