Comparison of the movement behaviour of experienced and novice performers during the Cat exercise.

Two previous studies showed kinematic differences between novice and experienced performers during unchoreographed movements executed in standing position. However, no study explores if these kinematic differences holds during unchoreographed movements executed in quadrupedal position. The aim of this study is to compare the movement behaviour of experienced and novice performers during an exercise wherein they are challenged to use dynamic and largely unchoreographed movement patterns executed in quadrupedal position. The exercise studied was the Cat exercise, in which participants were asked to behave like a feline for 10 minutes. An inventory of the chosen movements and the assessment of their average and coefficient of variation of the ground contact temporal parameters, computed by analysing the tri-dimensional whole-body kinematics of 25 performers (n = 13 novices and n = 12 experienced), was compared according to their experience level. No significant difference was found between the groups for the number of chosen movements, and median or coefficient of variation of ground contact temporal parameters, except for a greater foot/ knee swing coefficient of variation in experienced performers. This suggests that biomechanical constraints induced by quadrupedal position "prevent" a different selection of motor strategies by experienced performers, although the latter can be more variable in their movements.

Unravelling Motor Learning Processes in Theater Performers.

Theater performers, more than common actors, experience high physical loadings. This study aimed at analyzing the motor behavior of novice performers (dancers/actors who were introduced to the acting method of Jan Fabre) by investigating the kinematics of a physical acting exercise in a prospective study. Two measurement sessions were organized: before and after the novice performers (N = 13) took part in seven workshops. Total body kinematics were registered using a three-dimensional motion capture system. Using a principal component analysis, six factors were disseminated out of 30 kinematic parameters: Pelvic Motion, Speed of Progression, Lower Limb Position, Foot Motion, Lower Limb Motion, and Trunk Posture. Although no main effect of training was found for any of the factors (.429 < p < .964), Trunk Posture showed a higher consistency after the workshops. This study succeeded in providing insights in the motor behavior of theater performers and revealed recognizable features of motor learning.

Altered lumbopelvic movement control but not generalized joint hypermobility is associated with increased injury in dancers. A prospective study.

Dancers experience significant more low back pain (LBP) than non-dancers and are at increased risk of developing musculoskeletal injuries. Literature concerning the relationship between joint hypermobility and injury in dancers remains controversial. The purpose of this study was therefore to examine whether lumbopelvic movement control and/or generalized joint hypermobility would predict injuries in dancers. Four clinical tests examining the control of lumbopelvic movement during active hip movements were used in combination with joint hypermobility assessment in 32 dancers. Occurrence of musculoskeletal injuries, requiring time away from dancing, was recorded during a 6-month prospective study. Logistic regression analysis was used to predict the probability of developing lower limb and/or lumbar spine injuries. Twenty-six injuries were registered in 32 dancers. Forty-four percent of the dancers were hypermobile. A logistic regression model using two movement control tests, correctly allocated 78% of the dancers. The results suggest that the outcome of two lumbopelvic movement control tests is associated with an increased risk of developing lower extremities or lumbar spine injuries in dancers. Neither generalized joint hypermobility, evaluated with the Beighton score, nor a history of LBP was predictive of injuries. Further study of these interactions is required.