Muscle strength imbalances between the internal and external rotators of the shoulder are frequent in swimmers, but their role in shoulder injury remains unknown. We aimed to evaluate the association of shoulder rotator strength and injury in elite adolescent swimmers. Eighteen adolescent swimmers performed preseason isokinetic tests of the internal and external rotator muscles in concentric (con) and eccentric (ecc) modes. Conventional (conER:conIR and eccER:eccIR) and functional ratios (eccER:conIR and eccIR:conER) were calculated. Thirteen swimmers completed a weekly questionnaire about swimming habits and shoulder injuries throughout the season. Preseason testing showed a significant negative association between the functional eccER:conIR ratio and years of practice (p < 0.05). Over the season, 46% of athletes experienced at least one shoulder injury. At the end of the season, peak torques increased for both internal and external rotator muscles strength, but only concentrically, resulting in a decrease in the eccER:conIR functional ratio (p < 0.05). The receiver operating characteristic curve analysis highlighted good predictive power for the preseason functional eccER:conIR ratio, as values below 0.68 were associated with a 4.5-fold (95% CI 1.33-15.28, p < 0.05) increased risk of shoulder injuries during the season.
25 August 2020 in Clinical Journal of Sport Medicine
Objective: To determine the incidence and characteristics of injuries in elite badminton players over a competitive season. Design: Prospective cohort study. Setting: The French National Institute of Sport, Expertise, and Performance (INSEP). Participants: Twenty international elite badminton players. Independent Variables: The type, the location, the occurrence of the injury (match or training), the footwork type, the type of shot, and the perceived fatigue were collected. Main Outcome Measures: Injury incidence rates were calculated per 1000 hours of play (Hop). Results: Thirty-five injuries were collected over 10 210 hours of player exposure with an overall incidence rate of 3.4 injuries per 1000 Hop, with higher incidence during matches than training (11.6 vs 2.08; P < 0.05). Lower-limb injuries (LLI) were the most frequent (54.3%) especially on the foot (22.9%), and upper-limb injury rate (37.1%) was higher compared with previous studies. The most common type was musculotendinous injuries (51.4%). The smash and the lunge were the most frequent causes of upper-limb injury and LLI, respectively. Injuries occurred mostly during the first third of play (46.2%). Conclusions: This is the first prospective study to investigate badminton injuries among international badminton players. Further studies are needed to confirm our results on larger samples.
1 July 2013 in Annals of Physical and Rehabilitation Medicine
This study examined the association between knee proprioception, strength, and functional symmetry in healthy individuals using isokinetic strength tests, proprioception assessments, and hop tests. Twenty young, healthy adults (mean age 26.5 ± 4.1 years, 85% right-limb dominant) participated. Knee extensor and flexor strength were measured at 60°·s−1 and 240°·s−1. Proprioception was assessed by measuring passive joint position sense (JPS1: position recognition; JPS2: repositioning) and kinesthesia (threshold to detection of passive motion, TTDPM). Functional performance was evaluated using the single-leg hop test (SLH), triple-hop test (TH), and crossover hop test (COH). Symmetry was calculated using the limb symmetry index (LSI) as the ratio of non-dominant to dominant limb values. The results showed that THT (p = 0.011) and COH (p = 0.032) performance was superior on the dominant limb. A correlation analysis revealed strong positive correlations between hop test distances and knee extensor strength (r = 0.56–0.70, p < 0.001). JPS symmetry was negatively correlated with hop test symmetry (JPS1: SLH, r = −0.53; THT, r = −0.49; COH, r = −0.70). The participants with poorer position sense on the non-dominant leg were 2.7 times more likely to show LSI < 90% (p = 0.035). In conclusion, proprioception—particularly joint position sense—is associated with functional symmetry during dynamic tasks, highlighting the importance of proprioceptive assessments in rehabilitation and injury prevention.