In JoVE (1)

Other Publications (17)

Articles by Shaw Bronner in JoVE

 JoVE Behavior

fMRI Validation of fNIRS Measurements During a Naturalistic Task

1Department of Psychiatry, Yale School of Medicine, 2Department of Electronics and Bioinformatics, Meiji University, 3Department of Histology and Neurobiology, Dokkyo Medical University School of Medicine, 4ADAM Center, Department of Physical Therapy, Movement and Rehabilitation Sciences, Northeastern University, 5Department of Neurobiology, Yale School of Medicine

JoVE 52116

Other articles by Shaw Bronner on PubMed

Injuries in a Modern Dance Company: Effect of Comprehensive Management on Injury Incidence and Time Loss

The American Journal of Sports Medicine. May-Jun, 2003  |  Pubmed ID: 12750128

Professional dancers experience high rates of musculoskeletal injuries.

Gender and Limb Differences in Healthy Elite Dancers: Passé Kinematics

Journal of Motor Behavior. Jan, 2006  |  Pubmed ID: 16436364

Symmetry of skill development is emphasized in dance training, and many movements are well learned by both genders. The authors conducted a 2-dimensional kinematic analysis of a complex dance movement, the passé, in 12 healthy professional male and female dancers to determine whether there are differences between genders or limbs during the performance of that task. Only peak hip angular displacement differed in men and women. No differences were found between limbs in any of the dependent variables. Dancers displayed consistent temporal and spatial proximal-to-distal sequencing of movement coordination. Despite an indication of limb preference, as defined by gesture or stance limb, there were no differences in proficiency.

Management of a Delayed-union Sesamoid Fracture in a Dancer

The Journal of Orthopaedic and Sports Physical Therapy. Sep, 2007  |  Pubmed ID: 17939612

Misdiagnosed o sesamoid bone pathology in dancers may result in prolonged pain, disability, and career limitation. A thorough understanding of sesamoid disorders and appropriate treatment facilitates timely recovery. The potential loss of hallux plantar flexion strength consequent to sesamoidectomy is a major consideration for dancers.

Repair and Rehabilitation of Extensor Hallucis Longus and Brevis Tendon Lacerations in a Professional Dancer

The Journal of Orthopaedic and Sports Physical Therapy. Jun, 2008  |  Pubmed ID: 18515958

Case report.

Lower Extremity Kinetics in Tap Dance

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. 2010  |  Pubmed ID: 20214849

Tap dance is a unique performing art utilizing the lower extremities as percussion instruments. In a previous study these authors reported decreased injury prevalence among tap dancers compared to other dance and sports participants. No biomechanical analyses of tap dance exist to explain this finding. The purpose of the current pilot study was to provide a preliminary overview of normative peak kinetic and kinematic data, based on the hypothesis that tap dance generates relatively low ground reaction forces and joint forces and moments. Six professional tap dancers performed four common tap dance sequences that produced data captured by the use of a force platform and a five-camera motion analysis system. The mean vertical ground reaction force for all sequences was found to be 2.06+/-0.55 BW. Mean peak sagittal, frontal, and transverse plane joint moments (hip, knee, and ankle) ranged from 0.07 to 2.62 N.m/kg. These small ground reaction forces and joint forces and moments support our hypothesis, and may explain the relatively low injury incidence in tap dancers. Nevertheless, the analysis is highly complex, and other factors remain to be studied and clarified.

Pelvis and Hip Three-dimensional Kinematics in Grand Battement Movements

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. Mar, 2011  |  Pubmed ID: 21703090

Dancers frequently sustain hip injuries, including labral tears, coxa saltans, stress fractures, tendinosis, and joint disease. High velocity kicks (grand battement), with extreme abduction and external rotation (ER), may stress the hip, sacroiliac joint, and surrounding soft tissue. However, three-dimensional kinematic dance descriptions are limited. The purpose of this study was to describe the kinematics of the pelvis and hip in grand battement movements in healthy dancers. Seventeen advanced-level college dancers performed three battement conditions: battement devant to the front, à la seconde to the side, and derrière to the back. Data were collected with a 5-camera motion capture system. Repeated measures ANOVA (p < 0.05) compared peak pelvis and hip angular displacement and hip and toe velocity for all conditions and planes. Three-dimensional hip to pelvic ratios were calculated. There were differences in pelvic angular displacement between conditions in all planes (p < 0.00). Battement devant posterior pelvic tilt exceeded that of battement seconde. Both were opposite in direction from the anterior pelvic tilt of battement derrière. All conditions demonstrated pelvic obliquity toward the stance limb, with battement derrière greater than devant and seconde. Battement derrière transverse plane pelvic displacement exceeded that found in devant and seconde. There were also differences in hip angular displacement between conditions in all planes (p < 0.00). Battement derrière hip extension differed from battement devant and seconde flexion. The hip abducted in all conditions, with battement seconde exceeding devant and derrière. In the transverse plane, the hip rotated internally in battement seconde and externally in battement derrière and devant. In battement devant and seconde, peak hip ER decreased relative to baseline, while increasing at the peak of battement derrière. Battement peak velocities were relatively low. The ratio of hip to pelvic angular sagittal plane motion was 4.1, 2.6, and 0.5 in battement devant, seconde, and derrière respectively; 0.9, 2.6, and 1.5 in the frontal plane; and 0.6, 8.5, and 0.2 in the transverse plane. This confirms that pelvic motion provides a large proportion of the battement movement.

Parietal and Temporal Activity During a Multimodal Dance Video Game: an FNIRS Study

Neuroscience Letters. Oct, 2011  |  Pubmed ID: 21875646

Using functional near infrared spectroscopy (fNIRS) we studied how playing a dance video game employs coordinated activation of sensory-motor integration centers of the superior parietal lobe (SPL) and superior temporal gyrus (STG). Subjects played a dance video game, in a block design with 30s of activity alternating with 30s of rest, while changes in oxy-hemoglobin (oxy-Hb) levels were continuously measured. The game was modified to compare difficult (4-arrow), simple (2-arrow), and stepping conditions. Oxy-Hb levels were greatest with increased task difficulty. The quick-onset, trapezoidal time-course increase in SPL oxy-Hb levels reflected the on-off neuronal response of spatial orienting and rhythmic motor timing that were required during the activity. Slow-onset, bell-shaped increases in oxy-Hb levels observed in STG suggested the gradually increasing load of directing multisensory information to downstream processing centers associated with motor behavior and control. Differences in temporal relationships of SPL and STG oxy-Hb concentration levels may reflect the functional roles of these brain structures during the task period. NIRS permits insights into temporal relationships of cortical hemodynamics during real motor tasks.

Injuries in a Modern Dance Company Effect of Comprehensive Management on Injury Incidence and Cost

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. Sep, 2011  |  Pubmed ID: 22040757

Injury costs strain the finances of many dance companies. The objectives of this study were to analyze the effect of comprehensive management on injury patterns, incidence, and time loss and examine its financial impact on workers compensation premiums in a modern dance company. In this retrospective-prospective cohort study, injury was defined as any physical insult that required financial outlay (workers compensation or self insurance) or caused a dancer to cease dancing beyond the day of injury (time-loss injury). Injury data and insurance premiums were analyzed over an eight-year period. Injuries were compared using a mixed linear model with phase and gender as fixed effects. It was found that comprehensive management resulted in 34% decline in total injury incidence, 66% decrease in workers compensation claims, and 56% decrease in lost days. These outcomes achieved substantial savings in workers compensation premiums. Thus, this study demonstrates the effectiveness of an injury prevention program in reducing injury-related costs and promoting dancers' health and wellness in a modern dance company.

Differences in Segmental Coordination and Postural Control in a Multi-joint Dance Movement: Développé Arabesque

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. Mar, 2012  |  Pubmed ID: 22390951

Analysis of skill at multiple points on the learning continuum provides insight into how complex limb and postural organization is modified with extended practice. Dancers at three skill levels were compared performing a domain-specific movement (développé arabesque) to identify motor control parameters underlying skill acquisition of a sequential multi-joint trunk and extremity movement. It was hypothesized that general organization would be similar between groups, but that segmental coordination and postural control would differ with skill level. Twenty-seven expert, advanced, and intermediate dancers performed six repetitions of an arabesque sequence with the right limb. Data were acquired with a five-camera motion analysis system. Differences between groups in pelvis and gesture limb displacement, joint coordination patterns, and variability were determined using ANOVA with post hoc comparisons where applicable. Subjects displayed similar movement organization and timing. Differences were found in postural pelvic control and intra- and inter-limb coordination. These differences were most apparent during the arabesque phase. Control of the pelvis appears to be a key area that requires prolonged practice to master.

Activation of Dorsolateral Prefrontal Cortex in a Dual Neuropsychological Screening Test: an FMRI Approach

Behavioral and Brain Functions : BBF. 2012  |  Pubmed ID: 22640773

The Kana Pick-out Test (KPT), which uses Kana or Japanese symbols that represent syllables, requires parallel processing of discrete (pick-out) and continuous (reading) dual tasks. As a dual task, the KPT is thought to test working memory and executive function, particularly in the prefrontal cortex (PFC), and is widely used in Japan as a clinical screen for dementia. Nevertheless, there has been little neurological investigation into PFC activity during this test.

Energy Cost and Game Flow of 5 Exer-games in Trained Players

American Journal of Health Behavior. May, 2013  |  Pubmed ID: 23985184

To determine energy expenditure and player experience in exer-games designed for novel platforms.

Comparison of Steps and Energy Expenditure Assessment in Adults of Fitbit Tracker and Ultra to the Actical and Indirect Calorimetry

Journal of Medical Engineering & Technology. Oct, 2013  |  Pubmed ID: 24007317

Epidemic levels of inactivity are associated with chronic diseases and rising healthcare costs. To address this, accelerometers have been used to track levels of activity. The Fitbit and Fitbit Ultra are some of the newest commercially available accelerometers. The purpose of this study was to determine the reliability and validity of the Fitbit and Fitbit Ultra. Twenty-three subjects were fitted with two Fitbit and Fitbit Ultra accelerometers, two industry-standard accelerometers and an indirect calorimetry device. Subjects participated in 6-min bouts of treadmill walking, jogging and stair stepping. Results indicate the Fitbit and Fitbit Ultra are reliable and valid for activity monitoring (step counts) and determining energy expenditure while walking and jogging without an incline. The Fitbit and standard accelerometers under-estimated energy expenditure compared to indirect calorimetry for inclined activities. These data suggest the Fitbit and Fitbit Ultra are reliable and valid for monitoring over-ground energy expenditure.

Frontotemporal Oxyhemoglobin Dynamics Predict Performance Accuracy of Dance Simulation Gameplay: Temporal Characteristics of Top-down and Bottom-up Cortical Activities

NeuroImage. Jan, 2014  |  Pubmed ID: 23707582

We utilized the high temporal resolution of functional near-infrared spectroscopy to explore how sensory input (visual and rhythmic auditory cues) are processed in the cortical areas of multimodal integration to achieve coordinated motor output during unrestricted dance simulation gameplay. Using an open source clone of the dance simulation video game, Dance Dance Revolution, two cortical regions of interest were selected for study, the middle temporal gyrus (MTG) and the frontopolar cortex (FPC). We hypothesized that activity in the FPC would indicate top-down regulatory mechanisms of motor behavior; while that in the MTG would be sustained due to bottom-up integration of visual and auditory cues throughout the task. We also hypothesized that a correlation would exist between behavioral performance and the temporal patterns of the hemodynamic responses in these regions of interest. Results indicated that greater temporal accuracy of dance steps positively correlated with persistent activation of the MTG and with cumulative suppression of the FPC. When auditory cues were eliminated from the simulation, modifications in cortical responses were found depending on the gameplay performance. In the MTG, high-performance players showed an increase but low-performance players displayed a decrease in cumulative amount of the oxygenated hemoglobin response in the no music condition compared to that in the music condition. In the FPC, high-performance players showed relatively small variance in the activity regardless of the presence of auditory cues, while low-performance players showed larger differences in the activity between the no music and music conditions. These results suggest that the MTG plays an important role in the successful integration of visual and rhythmic cues and the FPC may work as top-down control to compensate for insufficient integrative ability of visual and rhythmic cues in the MTG. The relative relationships between these cortical areas indicated high- to low-performance levels when performing cued motor tasks. We propose that changes in these relationships can be monitored to gauge performance increases in motor learning and rehabilitation programs.

An Accelerated Step Test to Assess Dancer Pre-season Aerobic Fitness

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. Mar, 2014  |  Pubmed ID: 24568799

As the technical performance demands of dance increase, professional companies and pre-professional schools are implementing pre-season screenings that require an efficient, cost effective way to measure dancer aerobic fitness. The aim of this study was to assess an accelerated 3-minute step test (112 beats·min(-1)) by comparing it to the well-studied YMCA step test (96 beats·min(-1)) and a benchmark standard, an incremental treadmill test, using heart rate (HR) and oxygen consumption (VO2) as variables. Twenty-six professional and pre- professional dancers (age 20 ± 2.02 years) were fitted with a telemetric gas analysis system and HR monitor. They were tested in the following order: 96 step, 112 step, and treadmill test, with rest to return to baseline heart rate between each test. The step and treadmill tests were compared using Intra-class Correlation Coefficients [ICC (3, k)] calculated with analysis of variance (p < 0.05). To determine whether there was a relationship between peak and recovery HR (HRpeak, HRrecov) and VO2(VO2peak, VO2recov) variables, Pearson product moment correlations were used. Differences due to gender or group (pre- professionals versus professionals) were explored with MANOVAs for HRpeak, VO2peak, HRrecov, VO2recov, and fitness category. The 112 step test produced higher HRpeak and VO2peak values than the 96 step test, reflecting a greater workload (p < 0.001). For HRpeak, there were high correlations (r = 0.71) and for HRrecov, moderate correlations (r = 0.60) between the 112 step test and treadmill test. For VO2peak and VO2recov, there were moderate correlations between the 112 step test and treadmill test (r = 0.65 and 0.73). No differences between genders for VO2peak values were found for either step test, but males displayed lower HRpeak values for both step tests and higher VO2peak values during the treadmill test (p < 0.001). Recovery HR was lower in males for the 96 and 112 step tests (p < 0.05). This was reflected in higher fitness scores. There were no differences between groups in any of the variables when only females were compared. For the 112 step test, correlations between HRpeak and HRrecov were high (r = 0.85), and correlations between HRpeak and fitness category were very high (r = 0.98). It is concluded that the 112 step test provides an efficient, acceptable tool for testing dance populations, though further testing in larger groups of dancers representing a diverse range of genres and training levels is needed.

A Preseason Cardiorespiratory Profile of Dancers in Nine Professional Ballet and Modern Companies

Journal of Dance Medicine & Science : Official Publication of the International Association for Dance Medicine & Science. 2014  |  Pubmed ID: 24844424

While studies have investigated the physical demands of dance in terms of cardiorespiratory fitness, there are no recent comparisons of cardiorespiratory response to exercise among professional dancers of different genres. Our purpose was to: 1. develop a cardiorespiratory profile of professional dancers; 2. investigate differences in peak and recovery heart rate (HR) between professional modern and ballet dancers using an accelerated 3-minute step test; 3. demonstrate the relationship between cardiorespiratory variables; and 4. investigate the effects of company and work variables on the dancers' cardiorespiratory profiles. We hypothesized greater cardiorespiratory fitness in modern dancers than in ballet dancers, due to the nature of their repertory. Furthermore, we hypothesized that company profiles would reflect differences in work variables. Two hundred and eleven dancers (mean age 24.6 ± 4.7) from nine companies (two modern and seven ballet) performed a 3-minute step test. Demographics, height, mass, blood pressure (BP), smoking history, and resting peak and recovery HR were recorded. Body mass index (BMI) and fitness category were calculated. Independent t-tests were used to compare differences in demographics and cardiorespiratory variables due to genre, MANOVA were conducted to compare differences due to company, and correlations were calculated to determine the relationships between cardiorespiratory variables (p < 0.05). Modern dancers demonstrated higher mass and BMI, lower BP, lower resting HR and HR recovery, and a higher percentage were categorized as "fit" compared to ballet dancers (p < 0.03). There were differences between companies in age, experience, BMI, BP, resting, peak, and recovery HR, and fitness category (p < 0.001). The differences in cardiorespiratory fitness levels that may be related to rigor of repertory, rehearsal and performance seasons, or off-season exercise training are discussed. Results support the need for comprehensive physical fitness screening to identify dancers who could benefit from aerobic conditioning to enhance overall performance preparedness and to minimize fatigue effects.

Comparative Abilities of Microsoft Kinect and Vicon 3D Motion Capture for Gait Analysis

Journal of Medical Engineering & Technology. Jul, 2014  |  Pubmed ID: 24878252

Biomechanical analysis is a powerful tool in the evaluation of movement dysfunction in orthopaedic and neurologic populations. Three-dimensional (3D) motion capture systems are widely used, accurate systems, but are costly and not available in many clinical settings. The Microsoft Kinect™ has the potential to be used as an alternative low-cost motion analysis tool. The purpose of this study was to assess concurrent validity of the Kinect™ with Brekel Kinect software in comparison to Vicon Nexus during sagittal plane gait kinematics. Twenty healthy adults (nine male, 11 female) were tracked while walking and jogging at three velocities on a treadmill. Concurrent hip and knee peak flexion and extension and stride timing measurements were compared between Vicon and Kinect™. Although Kinect measurements were representative of normal gait, the Kinect™ generally under-estimated joint flexion and over-estimated extension. Kinect™ and Vicon hip angular displacement correlation was very low and error was large. Kinect™ knee measurements were somewhat better than hip, but were not consistent enough for clinical assessment. Correlation between Kinect™ and Vicon stride timing was high and error was fairly small. Variability in Kinect™ measurements was smallest at the slowest velocity. The Kinect™ has basic motion capture capabilities and with some minor adjustments will be an acceptable tool to measure stride timing, but sophisticated advances in software and hardware are necessary to improve Kinect™ sensitivity before it can be implemented for clinical use.

Physiological and Psychophysiological Responses to an Exer-game Training Protocol

Journal of Science and Medicine in Sport / Sports Medicine Australia. Mar, 2015  |  Pubmed ID: 25824058

Exer-games and virtual reality offer alternative opportunities to provide neuro-rehabilitation and exercise that are fun. Our goal was to determine how effective they are in achieving motor learning goals and fitness benefits as players gain experience.

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