Functional Movement Screening as a Predictor of Mechanical Loading and Performance in Dancers.

Dance requires effective functional movement for the prevention of injury, with implications for the biomechanical response to performance. This study investigated the efficacy of the Functional Movement Screening (FMS) in predicting mechanical loading during the Dance Aerobic Fitness Test (DAFT). Twenty-five university dancers (19 females; age: 20.3 ± 0.94 years; height: 162.55 ± 0.05 cm; mass: 58.73 ± 6.3 kg; and 6 males; age: 21.08 ± 2.01 years; height: 175 ± 6.54 cm; mass: 68.16 ± 4.97 kg) were screened using the FMS. Subjects then completed the DAFT with a GPS-mounted triaxial accelerometer located at the cervico-thoracic junction. Accelerometry data were sampled at 100 Hz and used to calculate total accumulated PlayerLoad, Playerload medial-lateral (PLML), PlayerLoad anterior-posterior (PLAP), and PlayerLoad vertical (PLV) over the duration of the DAFT. Linear regression analysis was used to determine the strength of correlation between FMS and PlayerLoad, PLML, PLAP, and PLV, and forward stepwise hierarchical modelling was performed to establish which FMS components were the primary predictors of mechanical loading. The Deep Squat (DS) demonstrated statistical significance for PLVTotal and PLTotal. The non-dominant Hurdle Step (HS) was a statistically significant predictor of PLMLTotal. The FMS composite score was a statistically significant predictor for PLVTotal. Forward stepwise regression analysis demonstrated that DS was the sole predictor for PLTotal and the primary predictor for PLVTotal. Non-dominant HS was identified as the primary predictor of PLMLTotal. It is concluded that the DS, non-dominant HS, and the FMS composite score can be used to predict mechanical loading in performance of the DAFT, which may have implications for dance performance and injury prevention.

Effect of Fatigue on Functional Movement Screening Performance in Dancers.

OBJECTIVE: Dance is associated with a high risk of injury, with fatigue identified as a contributing factor. Functional movement screening (FMS) has been used to identify alterations in normal movement which may contribute to injury risk, though this test is not normally performed in a fatigued state. The aim of this study was to determine whether fatigue induced by the dance aerobic fitness test (DAFT) results in changes in FMS scores with implications for performance and injury risk. METHODS: Forty-one university dancers completed the FMS before and immediately after completion of the DAFT. Rate of perceived exertion and heart rate were quantified as measures of fatigue. RESULTS: Post-DAFT, the mean FMS composite score (15.39±1.86) was significantly less (p≤0.01) than the pre-exercise score (16.83±1.83). Element-specific analysis revealed that the deep squat, non-dominant lunge, and dominant inline lunge scores were all significantly impaired post-DAFT (all p≤0.01). CONCLUSION: The identification of changes in quality of movement in a fatigued state suggests that movement screening should also be performed post-exercise to enhance screening for injury risk. The influence of dance-specific fatigue was FMS element-specific. Specifically, the deep squat and inline lunge were most susceptible to fatigue, with implications for injury risk and performance and reflective of the high level of neuromuscular control required.

Use of Triaxial Accelerometry During the Dance Aerobic Fitness Test: Considerations for Unit Positioning and Implications for Injury Risk and Performance.

Injury incidence in dance is high, in large part due to the frequency of repetitive and complex movements that require the lower limb to absorb and utilize extreme forces. The aim of this study was to quantify the biomechanical demands of the Dance Aerobic Fitness Test (DAFT) via triaxial accelerometry and utilize it to compare loading at the cervical spine and distal aspect of the lower limb. University dancers (N = 26; age: 20.0 ± 1.5 years; height: 1.61 ± 0.08 m; body mass: 58.40 ± 6.20 kg) completed two trials (one familiarization and one experimental) of the DAFT, consisting of five incremental levels of dance performance. Micromechanical electrical systems (MEMS) accelerometry was used to calculate total accumulated PlayerLoad (PLTotal) and it's uniaxial (anteroposterior [PLAP], mediolateral [PLML], and vertical [PLV]) components for each level. MEMS units were positioned at cervical vertebra 7 (C7) and the center of gastrocnemius (LL). There was a significant main effect for each level, with loading increasing in relation to exercise duration. There was also a significant main effect for anatomical placement, with higher PLTotal (C7 = 41.05 ± 7.31 au; LL = 132.58 ± 35.70), PLAP (C7 = 12.96 ± 2.89 au; LL = 47.16 ± 13.18 au), and PLML (C7 = 10.68 ± 2.15; LL = 46.29 ± 12.62 au) at LL when compared to C7, with the converse relationship for PLV (LL = 20.05 ± 3.41 au; C7 = 44.89 ± 11.22 au). Significant interactions were displayed for all PL metrics. It is concluded that triaxial PlayerLoad was sensitive enough to detect increased loading associated with increases in exercise intensity, while lower limb accelerometer placement detected higher loading in all planes. The specificity in anatomical placement has practical implications, with lower limb accelerometry recommended to assess movement strategies in that location.

The Influence of Fatigue on Star Excursion Balance Test Performance in Dancers.

Dance is associated with a high risk of injury and fatigue is often a contributing factor. The Star Excursion Balance Test (SEBT) has been used to identify alterations in normal movement that may contribute to injury risk; however, there has been limited investigation of the potential effects of fatigue. The aim of this study was to explore the influence of dance-specific fatigue on SEBT performance, with implications for injury and performance in dance. Thirty-five university dancers completed the modified SEBT in anterior, posterolateral, and posteromedial directions prior to and immediately following the Dance Aerobic Fitness Test (DAFT). The SEBT was completed for dominant and non-dominant legs. Heart rate and rate of perceived exertion were quantified as measures of fatigue. Post-DAFT, the mean SEBT percentage maximized reach distances for dominant and nondominant legs were non-significant compared to pre-DAFT scores. Lack of a main effect for exercise was observed in each of the anterior dominant and non-dominant, posterolateral dominant and non-dominant, and posteromedial dominant and non-dominant scores. It is concluded that the limited changes in the ability of dancers to perform the SEBT suggest that they were able to maintain SEBT performance in both dominant and non-dominant legs following exercise. This resistance to fatigue may demonstrate a dance-specific performance adaptation so that potential alterations in movement performance that may increase injury risk were not observed.