Effect of the frequency of weight-free vibration training on the isokinetic strength of knee muscles in juvenile football players

The work stress, occupational burnout, coping strategies and organizational support of elite sports coaches in Sichuan Province: the mediating role of organizational support

Objective

This study investigated the relationships between job pressure, occupational burnout, organizational support and coping strategies among competitive sports coaches in Sichuan Province, China. It also assesses the impact of job pressure on occupational burnout and the mediating roles of organizational support and coping strategies.

Methods

A survey was conducted with 207 competitive sports coaches from Sichuan Province, China. Basic information and data on job pressure, occupational burnout, organizational support and coping strategies were collected. Correlations between variables were analyzed, and a theoretical model for hypothesizing the mediating effects was established. A multiple regression model was used to predict the relationships between occupational burnout and job pressure, organizational support and coping strategies.

Results

(1) Job pressure was significantly positively correlated with occupational burnout (R = 0.436, p < 0.001) and negative coping (R = 0.389, p < 0.001) but significantly negatively correlated with organizational support (R = -0.503, p < 0.001). Occupational burnout was significantly negatively correlated with academic title (R = -0.158, p = 0.023) and organizational support (R = -0.349, p < 0.001) but significantly positively correlated with negative coping (R = 0.440, p < 0.001). Organisational support was significantly positively correlated with positive coping (R = 0.222, p = 0.001) but significantly negatively correlated with negative coping (R = -0.207, p = 0.003). (2) Mediating effects: Job pressure indirectly affects occupational burnout via organizational support and negative coping strategies. (3) Multiple regression: Y1 (Job Pressure) = 69.262 + 1.172 × Emotional Exhaustion -2.231 × Emotional Support +1.041 × Negative Coping -6.554 × Academic Title (from high to low). Y2 (Occupational Burnout) = 25.609 + 0.141 × Job Pressure - 0.306 × Organisational Support +0.620 × Negative Coping -2.097 × Academic Title.

Conclusion

Job pressure is a significant factor leading to occupational burnout among competitive sports coaches in Sichuan Province, China, and factors such as role, interpersonal relationships and career development are closely related to occupational burnout. The sense of organizational support and negative coping strategies play a mediating role between job pressure and occupational burnout. Reducing emotional exhaustion and negative coping, enhancing emotional support and improving the academic titles of coaches can help to reduce job pressure and occupational burnout among competitive sports coaches in Sichuan Province.

Effect of strength training with additional acupuncture on balance, ankle sensation, and isokinetic muscle strength in chronic ankle instability among college students

Purpose: The effects of the combination of strength training and acupuncture on chronic ankle instability have not been studied. This study examined effects of strength training combined with acupuncture on balance ability, ankle motion perception, and muscle strength in chronic ankle instability among college students. Methods: Forty-six chronic ankle instability college students were randomly categorized into the experimental group (n = 24, strength training + acupuncture) and the control group (n = 22, strength training) for an 8-week intervention. Results: For the results at 8 weeks, compared with the baseline, in the experimental group, the chronic Ankle Instability Tool (CAIT) score, ankle dorsiflexion, plantar flex, eversion peak torque (60°/s), and plantar flex peak torque (180°/s) increased by 13.7%, 39.4%, 13.7%, 14.2%, and 12.3%, respectively. Dorsiflexion, plantar flexion, inversion, and eversion kinesthetic sensation test angles decreased by 17.4%, 20.6%, 15.0%, and 17.2%, respectively. Anterior-posterior and medial-lateral displacement, and anterior-posterior and medial-lateral velocity decreased by 28.9%, 31.6%, 33.3%, and 12.4%, respectively. Anterior-posterior and medial-lateral displacement, and anterior-posterior and medial-lateral mean velocity decreased by 28.9%, 31.6%, 33.3%, and 12.4%, respectively. In the control group, the Cumberland Ankle Instability Tool score and the ankle dorsiflexion peak torque (60°/s) increased by 13.8% and 17.9%, respectively. The inversion kinesthetic sensation test angle decreased by 15.2%, whereas anterior-posterior and medial-lateral displacement, and anterior-posterior and medial-lateral mean velocity decreased by 17.1%, 29.4%, 12.3%, and 16.8%, respectively. 2) For the comparison between the groups after 8 weeks, the values of ankle dorsiflexion and plantar flex peak torque (60°/s) in the experimental group were greater than those in the control group. The values of ankle plantar flex kinesthetic sensation test angle, the anterior-posterior displacement, and anterior-posterior mean velocity in the experimental group were lower than those in the control group. Conclusion: Acupuncture treatment in conjunction with muscle strength training can further improve the balance ability of anterior-posterior, ankle dorsiflexion, and plantar flex strength and plantar flex motion perception in chronic ankle instability participants.

Effects of ankle isokinetic training on muscle strength and balance amongst older women with mild Parkinson's disease: A randomised trial

BACKGROUND

Patients with Parkinson's disease frequently experience problems with balance and gait.

OBJECTIVE

This study examined the influences of regular ankle isokinetic muscle strength training on muscle strength and balance ability amongst elderly women with mild Parkinson's disease.

METHODS

A total of 55 elderly women with mild Parkinson's disease were randomly divided into the experimental group (n= 28) and the control group (n= 27) for 16 weeks. The experimental group was trained for 16 weeks by using isokinetic muscle strength training.

RESULTS

After 16 weeks of training in the experimental group, the peak torque (PT) of ankle (average of the left and right sides) dorsiflexion, plantarflexion, eversion and inversion, and the standing balance index revealed that the left and right stability and overall stability indexes significantly increased by 25.9%, 43.5%, 62.7%, 82.8%, 37.1% and 32.2%, respectively (p< 0.05). The experimental group exhibited significantly increased PT of ankle dorsiflexion, plantarflexion, eversion and inversion. Moreover, the left and right stability and overall stability indexes were significantly improved compared with those of the control group (p< 0.05). This study found a linear regression relationship between the PT of ankle inversion and overall stability index.

CONCLUSION

This study determined that ankle isokinetic muscle strength training improved ankle dorsiflexion, plantarflexion, eversion and inversion muscle strength, and balance ability amongst elderly women with mild Parkinson's disease. However, it did not improve stability in the anterior and posterior directions. Ankle inversion muscle strength is more likely to affect overall balance.

Effects of whole-body vibration training combined with KAATSU training on lower limb joint muscle strength in older women

Objective: This study aimed to investigate the effect of whole-body vibration training (WBVT) combined with KAATSU training (KT) on lower limb joint muscle strength and to provide a reference for improving muscle strength in older women. Methods: A total of 86 healthy older people was randomly divided into WBVT group (WG, n = 21), KT group (KG, n = 22), combined intervention group (CIG, n = 20) and control group (CG, n = 23). WG and CIG subjects underwent WBVT, and KG and CIG subjects underwent 150 mmHg and lower limb joint and local compression intervention for 16 weeks (three times per week, about 15 min/time). The peak torque (PT) and endurance ratio (ER) of joint flexion or extension were tested for all subjects. Results: 1) Results at 16 weeks were compared with the baseline data. The knee extension and ankle flexion PT (60°/s) in CIG increased by 14.3% and 15.3%, respectively (p < 0.05). The knee extension PT (180°/s) increased by 16.9, 18.4% and 33.3% in WG, KG and CIG (p < 0.05), respectively, and the ankle extension PT (180°/s) in CIG increased by 31.1% (p < 0.05). The hip, knee extension and ankle flexion ER increased by 10.0, 10.9% and 5.7% in CIG (p < 0.05), respectively. 2) Results were compared among groups at 16 weeks. The relative changes were significantly lower in WG, KG and CG compared to CIG in the knee extension and ankle flexion PT (60°/s) (p < 0.05). The relative changes were significantly greater in WG, KG and CIG compared to CG in the knee extension PT (180°/s) (p < 0.05). The relative changes were significantly lower in WG, KG and CG compared to CIG in the ankle extension PT (180°/s) (p < 0.05). The relative changes were significantly lower in WG, KG and CG compared to CIG in the hip extension ER (p < 0.05). The relative changes were significantly lower in CG compared to CIG in the knee extension ER (p < 0.05). Conclusion: Sixteen-week WBVT and KT increased the knee extensor strength in older women. Compared with a single intervention, the combined intervention had better improvements in the knee extensor and ankle flexor and extensor strength and hip extension muscle endurance. Appears to be some additional benefit from combined intervention above those derived from single-interventions.

Effects of traditional Chinese eight brocade exercise with same frequency and different durations on the quality of life, 6-min walk and brain natriuretic peptide in patients with chronic heart failure

BACKGROUND

Traditional Chinese eight brocade exercise (TCEBE) with same cycle and frequency and different durations has an effect on patients with chronic heart failure (CHF). However, relevant reports on the topic are lacking.

OBJECTIVE

This study aims to explore the differences of rehabilitation effect by conducting TCEBE with the same cycle and frequency and different single exercise time for patients with CHF.

METHODS

A total of 103 patients with CHF were randomly divided into long-time group (LTG), short-time group (STG) and control group (CG). The subjects in the three groups were given corresponding routine treatment. In addition, under the guidance of professional TCEBE coaches and nurses, TCEBE was conducted for 12 weeks (3 times/week) for LTG (60 min/time) and STG (30 min/time). Minnesota living with heart failure questionnaire (MLHFQ) was used, and 6-min walk (6MWK) and brain nautical peptide (BNP) were tested.

RESULTS

1) At 12 weeks, the comparison between groups obtained the following results: For the LTG, MLHFQ was less than that of the CG (P < 0.01), 6MWT was greater than that of the CG (P < 0.05), and 6MWT was greater than that of the STG (P < 0.05); for the STG, MLHFQ was less than that of the CG (P < 0.05); no significant difference in BNP was found among the three groups; 2) At 12 weeks and 0 weeks, the comparison obtained the following results: For the LTG, MLHFQ decreased by 37.7 %, and 6MWT increased by 46.7 % (P < 0.01); for the STG, MLHFQ decreased by 31.7 %, and 6MWT increased by 31.5 % (P < 0.01); for the CG, MLHFQ decreased by 14.6 %, and 6MWT increased by 19.7 % (P < 0.05); no significant change in BNP was found in each group.

CONCLUSION

TCEBE of two kinds of duration improves the quality of life and 6MWT of patients with CHF but has no positive effect on BNP. Compared with 30-min/time, 60-min/time further improves 6MWT in patients with CHF but has no additional benefit on quality of life.

Effect of vertical vibration stimulation at different frequencies on delayed muscle soreness in athletes: A randomized trial

Background

The effect of stimulation with different vibration frequencies on delayed muscle soreness (DOMS) has not yet been determined. This study was conducted to investigate the effect of medium- and high-frequency vertical vibration stimulation on DOMS in track and field athletes.

Methods

A total of 38 elite men's track and field athletes were recruited during the off-season. Through the digital randomization method, the participants were divided into three groups. Two-knee DOMS modeling was performed on the medium-frequency group (MFG, 25 Hz, n = 13), high-frequency group (HFG, 50 Hz, n = 12) and control group (CG, 0 Hz, n = 13). The three groups were matched in age, height and body mass. Vertical vibration stimulation was performed for 10 min on the MFG and HFG. Visual analog score (VAS); interleukin-6 (IL-6), lactic dehydrogenase (LDH) and creatine kinase (CK) levels and knee extension peak torque (PT) were determined immediately and at 24, 48, and 72 h after vibration.

Results

The 48 and 72 h VASs of the HFG were lower than those of the MFG and CG. The immediate and 24 and 48 h IL-6 concentrations in the HFG were lower than those in the CG. The 24 h IL-6 concentration in the HFG was lower than that in the MFG and that in the MFG was lower than that in the CG. LDH concentrations at different time points did not differ amongst groups. Immediate and 24 h CK concentrations were lower in the HFG than in the CG. The immediate and 24, 48, and 72 h knee extensions at 60°/s PT were lower in the HFG than in the CG. The immediate and 24 and 48 h knee extension at 60 °/s PT in the MFG were lower than those in the CG. The 24 h knee extension (240°/s peak torque) value in the HFG was lower than that in the CG.

Conclusion

Stimulation with 50 Hz (amplitude of 3 mm) vibration can reduce the muscle pain, IL-6 and CK concentrations and knee extension loss caused by DOMS. However, stimulation with 25 Hz (amplitude of 3 mm) vibration had poor effects. Results suggested that high-frequency vibration training is an effective strategy for relieving DOMS after intensive training.