The Effect of 6-Week Combined Balance and Plyometric Training on Change of Direction Performance of Elite Badminton Players

The study aimed to investigate the effect of combined balance and plyometric training on the change of direction (COD) performance of badminton athletes. Sixteen elite male badminton players volunteered to participate and were randomly assigned to a balance-plyometric group (BP: n = 8) and plyometric group (PL: n = 8). The BP group performed balance combined with plyometric training three times a week over 6 weeks; while the PL group undertook only plyometric training three times a week during the same period. Meanwhile, both groups were given the same technical training. All participants were tested to assess the COD ability before and after the training period: Southeast Missouri (SEMO) test and 5-0-5 test, dynamic balance ability (Y-Balance test, YBT), and reactive strength index (RSI). Repeated-measure ANOVA revealed that after the intervention there was a significant time × group interaction for 5-0-5 COD test, YBT of both legs and RSI (p < 0.05, partial η2 = 0.26–0.58) due to the better performance observed at post-test compared with a pre-test for the BP group [effect size (ES) = 1.20–1.76], and the improvement was higher than that of the PL group. The change in SEMO test did not differ between BP and PL (p < 0.159, partial η2= 0.137), but the magnitude of the with-group improvement for BP (ES = 1.55) was higher than that of PL (ES = 0.81). These findings suggest that combined training could further improve the COD performance of badminton athletes than plyometric training alone and might provide fitness trainers a more efficient COD training alternative

The influence of non-haematological factors on the development of ankle arthropathy in haemophilia

Haemophilia is an inherited condition in which circulating blood clotting factors are much reduced or absent resulting in the tendency to bleed into joint cavities where the ankle is the most commonly affected. Prophylactic replacement of clotting factors has much improved joint health in the majority of people with haemophilia however many continue to develop joint disease. Purpose. To explore the potential for non-haematological factors to influence the development of haemophilic arthropathy at the ankle. Methods. This study had two phases. Factors for investigation were determined using a Delphi process and subsequently preliminary clinical instrument testing occurred. Finally a case-control correlational study was carried out to investigate the presence of selected factors in a haemophilia cohort compared with normal volunteers. Results. Forty-two factors reached consensus from the Delphi Process of which 22 were selected for onward investigation comprising musculoskeletal, exercise, and haematological factors. In a case-control study with 90 participants, six factors successfully differentiated the Haemophilia Ankle group from the others. A further three factors separated people with haemophilia from normal volunteers representing musculoskeletal differences that cannot be attributed to arthropathy. A regression model was developed comprising: the Ankle Lunge Test, Foot and Ankle Ability Measure (FAAM), Duration of Exposure to a key sport and Subtalar joint inversion which correctly predicted 89.7% of cases with 86.7% sensitivity and 92.9% specificity. Conclusions. These results represent the first attempt to understand the interaction of factors that influence the arthropathy development. The FAAM sports subscale and Duration of Exposure to a key sport were identified as independent variables with the strongest association with haemophilic arthropathy at the ankle. Avenues for physiotherapeutic intervention have been identified with preventative screening tools and pre-habilitation programmes possible for young boys with haemophilia at risk of developing this debilitating condition