Using Free Internet Videogames in Upper Extremity Motor Training for Children with Cerebral Palsy.

Movement therapy is one type of upper extremity intervention for children with cerebral palsy (CP) to improve function. It requires high-intensity, repetitive and task-specific training. Tedium and lack of motivation are substantial barriers to completing the training. An approach to overcome these barriers is to couple the movement therapy with videogames. This investigation: (1) tested the feasibility of delivering a free Internet videogame upper extremity motor intervention to four children with CP (aged 8-17 years) with mild to moderate limitations to upper limb function; and (2) determined the level of intrinsic motivation during the intervention. The intervention used free Internet videogames in conjunction with the Microsoft Kinect motion sensor and the Flexible Action and Articulated Skeleton Toolkit software (FAAST) software. Results indicated that the intervention could be successfully delivered in the laboratory and the home, and pre- and post- impairment, function and performance assessments were possible. Results also indicated a high level of motivation among the participants. It was concluded that the use of inexpensive hardware and software in conjunction with free Internet videogames has the potential to be very motivating in helping to improve the upper extremity abilities of children with CP. Future work should include results from additional participants and from a control group in a randomized controlled trial to establish efficacy.

Reliability and validity of the Microsoft Kinect for assessment of manual wheelchair propulsion.

Concurrent validity and test-retest reliability of the Microsoft Kinect in quantification of manual wheelchair propulsion were examined. Data were collected from five manual wheelchair users on a roller system. Three Kinect sensors were used to assess test-retest reliability with a still pose. Three systems were used to assess concurrent validity of the Kinect to measure propulsion kinematics (joint angles, push loop characteristics): Kinect, Motion Analysis, and Dartfish ProSuite (Dartfish joint angles were limited to shoulder and elbow flexion). Intraclass correlation coefficients revealed good reliability (0.87-0.99) between five of the six joint angles (neck flexion, shoulder flexion, shoulder abduction, elbow flexion, wrist flexion). ICCs suggested good concurrent validity for elbow flexion between the Kinect and Dartfish and between the Kinect and Motion Analysis. Good concurrent validity was revealed for maximum height, hand-axle relationship, and maximum area (0.92-0.95) between the Kinect and Dartfish and maximum height and hand-axle relationship (0.89-0.96) between the Kinect and Motion Analysis. Analysis of variance revealed significant differences (p < 0.05) in maximum length between Dartfish (mean 58.76 cm) and the Kinect (40.16 cm). Results pose promising research and clinical implications for propulsion assessment and overuse injury prevention with the application of current findings to future technology.

Trunk and neck kinematics during overground manual wheelchair propulsion in persons with tetraplegia.

PURPOSE: To test the hypothesis that movement of the head and trunk increases as a consequence of speed during manual wheelchair propulsion over the ground in individuals with tetraplegia. METHODS: Seven adult participants with tetraplegia who used manual wheelchairs (5 men and 2 women, aged 33.0 ± 10.2) were selected for the study. Participants propelled over the ground at three different speeds while video motion capture methods collected kinematic data. Variables investigated were forward flexion, lateral flexion and axial rotation for both the head and trunk. Repeated measures ANOVA were used to determine effects of speed on head and trunk movements. RESULTS: Both neck and trunk forward flexion significantly increased as a result of speed (p = 0.034, p = 0.031), with a large effect size (r = 0.6, r = 0.6) between slow and fast speeds. Lateral flexion and axial rotation were minimal for the neck and trunk and did not significantly increase with speed. CONCLUSIONS: Results suggest that manual wheelchair users with tetraplegia compensate for trunk muscle weakness by flexing the upper trunk and neck forward during manual wheelchair propulsion and that these movements increase with speed. Further studies should examine if these movements relate to overuse injuries and interventions that focus on improving manual wheelchair biomechanics of individuals with tetraplegia. IMPLICATIONS FOR REHABILITATION: Individuals who use manual wheelchairs utilize their upper extremities almost exclusively for both everyday mobility and participation in daily life activities which can often lead to overuse injuries and pain. Despite having a lack of trunk muscle innervation, manual wheelchair users with tetraplegia are able to compensate for this weakness by using the upper trunk and neck. The way in which force is translated from the trunk through the upper extremities to the pushrim may impact propulsion biomechanics, and ultimately the extent in which upper extremity pain and injury develops. A better understanding of how individuals with trunk impairments propel a manual wheelchair will help clinicians determine optimal wheelchair positioning and training during rehabilitation for individuals with tetraplegia. Clinicians can determine ways in which they can support manual wheelchair users to allow for most efficient biomechanics.

Effect of hippotherapy on motor control, adaptive behaviors, and participation in children with autism spectrum disorder: a pilot study.

OBJECTIVE: The purpose of this investigation was to determine whether hippotherapy increased function and participation in children with autism spectrum disorder (ASD). We hypothesized improvements in motor control, which might increase adaptive behaviors and participation in daily activities. METHOD: Six children with ASD ages 5-12 participated in 12 weekly 45-min hippotherapy sessions. Measures pre- and post-hippotherapy included the Vineland Adaptive Behavior Scales-II and the Child Activity Card Sort. Motor control was measured preintervention and postintervention using a video motion capture system and force plates. RESULTS: Postural sway significantly decreased postintervention. Significant increases were observed in overall adaptive behaviors (receptive communication and coping) and in participation in self-care, low-demand leisure, and social interactions. CONCLUSION: These results suggest that hippotherapy has a positive influence on children with ASD and can be a useful treatment tool for this population.

Cervical spine motion during extrication.

BACKGROUND: It has been estimated that up to one-quarter of spinal cord injuries may be significantly worsened during extrication or early treatment after a motor vehicle accident. STUDY OBJECTIVES: The purpose of this study was to analyze the planar motions of the head relative to the torso during extrication from an automobile in a laboratory setting. METHODS: Video motion capture was used to quantify the range of motion of the head relative to the torso in 10 participants as they were extricated from a mock motor vehicle during four different extrication techniques: 1) Unassisted Unprotected, 2) Unassisted Protected with a cervical collar (CC), 3) Assisted and Protected with a CC, and 4) Assisted and Protected with a CC and Kendrick Extrication Device. RESULTS: The results indicated a significant decrease in movement for all motions when the driver exited the vehicle unassisted with CC protection, compared to exiting unassisted and without protection. Decreases in movement were also observed for an event (i.e., Pivot in seat) during extrication with paramedic assistance and protection. However, no movement reduction was observed in another event (i.e., Recline on board) with both paramedic assistance and protection. CONCLUSION: In this study, no decrease in neck movement occurred for certain extrication events that included protection and assistance by the paramedics. Future work should further investigate this finding.

Stroke Survivors' Gait Adaptations to a Powered Ankle Foot Orthosis.

BACKGROUND AND PURPOSE: Stroke is the leading cause of long term disability in the United States, and for many it causes loss of gait function. The purpose of this research is to examine stroke survivors' gait adaptations to training on the Powered Ankle Foot Orthosis (PAFO). Of particular interest is the stroke survivors' ability to learn how to store and release energy properly while using the device. The PAFO utilizes robotic tendon technology and supports motion with a single degree of freedom, ankle rotation in the sagittal plane. This actuator comprises a motor and series spring. The user interacts with the output side of the spring while the robot controls the input side of the spring such that typical able body ankle moments would be generated, assuming able body ankle kinematics are seen at the output side of the spring. METHODS: Three individuals post-stroke participated in a three week training protocol. Outcome measures (temporal, kinematic, and kinetic) were derived from robot sensors and recorded for every step. These data are used to evaluate each stroke survivor's adaptations to robotic gait assistance. The robot was worn only on the paretic ankle. For validation of the kinematic results, motion capture data were collected on the third subject. RESULTS: All subjects showed increased cadence, ankle range of motion, and power generation capabilities. Additionally, all subjects were able to achieve a larger power output than power input from the robot. Motion capture data collected from subject three validated the robot sensor kinematic data on the affected side, but also demonstrated an unexpected gait adaptation on the unaffected ankle. CONCLUSIONS: Sensors on the gait assisting robot provide large volumes of valuable information on how gait parameters change over time. We have developed key gait evaluation metrics based on the available robot sensor information that may be useful to future researchers. All subjects adapted their gait to the robotic assistance, and many of their key metrics moved closer to typical able body values. This suggests that each subject learned to utilize the assistive moments generated by the robot, despite having no predefined ankle trajectory input from the robot. The security of being harnessed on the treadmill led to more dramatic and favorable results.

Changes in dynamic trunk/head stability and functional reach after hippotherapy.

OBJECTIVES: To determine if hippotherapy (therapy using a horse) improves head/trunk stability and upper extremity (UE) reaching/targeting in children with spastic diplegia cerebral palsy (SDCP). DESIGN: Pre-postoperative follow-up with a 12-week intervention and 12-week washout period after intervention. SETTING: A human performance laboratory with 6 camera video motion capture systems for testing. PARTICIPANTS: Eleven children (age 5-13y, average 8y) with SDCP, 8 children (age 5-13y, average 8y) without disabilities. INTERVENTION: Hippotherapy intervention performed at 3 therapeutic horseback riding centers. MAIN OUTCOME MEASURES: Video motion capture using surface markers collecting data at 60 Hz, a mechanical barrel to challenge trunk and head stability, and functional reach/targeting test on static surface. RESULTS: Significant changes with large effect sizes in head/trunk stability and reaching/targeting, elapsed time, and efficiency (reach/path ratio) after 12 weeks of hippotherapy intervention. Changes were retained after a 12-week washout period. CONCLUSIONS: Hippotherapy improves trunk/head stability and UE reaching/targeting. These skills form the foundation for many functional tasks. Changes are maintained after the intervention ceases providing a skill foundation for functional tasks that may also enhance occupational performance and participation.

Pulmonary valve replacement: a comparison of three biological valves.

BACKGROUND: We retrospectively reviewed the performance of the mosaic porcine, bovine pericardial, and homograft prostheses for pulmonary valve replacement to correct chronic pulmonary insufficiency. METHODS: From January 1995 to August 2006, 82 patients (mean age, 22.7 years) underwent valve replacement with porcine (49 patients), bovine pericardial (18 patients), or pulmonary homograft (15 patients) prosthesis at a mean of 15.3 years after initial outflow tract reconstruction. Excluded were patients with extracardiac conduits, monocusp valves, or the Ross procedure. The groups were similar with respect to age, body surface area, degree of regurgitation, right ventricular dimension, right ventricular to pulmonary artery gradient, and valve size. Follow-up was longer in the homograft cohort (porcine, 20 +/- 27 months; pericardial, 42 +/- 21; homograft, 49 +/- 40; p < 0.01). RESULTS: All three prostheses significantly reduce chronic pulmonary regurgitation, but late insufficiency was higher with homografts. Right ventricular dimension was significantly reduced in the stented but not the allograft cohorts. Late valve dysfunction was highest with homografts (54%), followed by porcine (19%) and pericardial valves (5.5%; p < 0.05. Functional class and mild to moderate tricuspid insufficiency significantly improved with pulmonary valve replacement. Early and late mortality was 3.6% and 1.2%, respectively. CONCLUSIONS: All three prostheses performed similarly for 3 years. Pulmonary regurgitation developed more frequently in homografts albeit at a longer duration of follow-up.

A comparison of artificial turf.

BACKGROUND: In an attempt to decrease injuries, newer forms of artificial turf have been marketed. The purpose of this study was to determine whether a new shredded rubber-based turf improves impact attenuation. METHODS: An instrumented computerized impact recording device (IRD, Techmark, Lansing, MI) was dropped 20 times from a height of 48 inches onto five types of turf used by a professional football team. RESULTS: Duncan's multiple range test shows that the new rubber-based field and the older foam field are not significantly different. There were significant differences, however, between sites on the shredded rubber-based field. CONCLUSION: The change from a foam-based system to a shredded rubber-based system had no effect on impact attenuation overall. However, areas in the shredded rubber-based field were significantly compacted, causing some sites to be much harder than the foam-based surface it replaced.

Linear and angular head accelerations during heading of a soccer ball.

PURPOSE: Cognitive deficits observed in professional soccer players may be related to heading of a soccer ball. To assess the severity of a single instance of heading a soccer ball, this study experimentally and theoretically evaluated the linear and angular accelerations experienced by the human head during a frontal heading maneuver. METHODS: Accelerations were measured using a set of three triaxial accelerometers mounted to the head of each of four adult male subjects. These measurements (nine signals) were used to estimate the linear acceleration of the mass center and the angular acceleration of the head. Results were obtained for ball speeds of 9 and 12 m.s(-1) (approximately 20 and 26 mph). A simple mathematical model was derived for comparison. RESULTS: At 9 m.s(-1), peak linear acceleration of the head was 158 +/- 19 m.s(-2) (mean +/- standard deviation) and peak angular acceleration was 1302 +/- 324 rad.s(-2); at 12 m.s(-1), the values were 199 +/- 27 m.s-2 and 1457 +/- 297 rad.s-2, respectively. The initial acceleration pulses lasted approximately 25 ms. Measured head accelerations confirmed laboratory headform measurements reported in the literature and fell within the ranges predicted by the theoretical model. CONCLUSIONS: Linear and angular acceleration levels for a single heading maneuver were well below those thought to be associated with traumatic brain injury, as were computed values of the Gadd Severity Index and the Head Injury Criterion. However, the effect of repeated acceleration at this relatively low level is unknown.

Does soccer headgear attenuate the impact when heading a soccer ball?

UNLABELLED: There is increasing concern that repetitive blows to the head, such as those from heading a soccer ball, can cause measurable cognitive impairment. Reducing acceleration of impact could reduce neurologic sequelae. OBJECTIVE: To measure the effectiveness of four different types of soccer headgear in reducing the acceleration of impact. METHODS: A standard magnesium headform was instrumented with a triaxial accelerometer. A soccer ball was propelled at the headform at three different speeds known to occur in soccer play: 9, 12, and 15 m/sec (20, 26, and 34 mph). The main outcome was the peak acceleration of the headform associated with these impacts with and without protective headgear. RESULTS: Peak accelerations were found in a range from 144 m/s(2) to 289 m/s(2) (14.67-29.5 G, G = 9.81 m/s(2)). Using multivariate analysis of variance (MANOVA) methods to compare the headbands and controls, there was no significant difference in the measured accelerations at the center of gravity with or without headgear (p = 0.50). However, the interaction term of headbands, pressure, and speed was significant at F = 5.51 and p = 0.00001. Using contrasts within conditions, some headbands were found to cause a decrease in peak acceleration at the highest speed and pressure. CONCLUSIONS: Currently available headgear for soccer heading shows little ability to attenuate impact during simulated soccer heading. However, statistically significant decreases are present at the highest speeds and pressures tested, suggesting the headbands may play a role in decreasing impact for more forceful blows.

Does the use of artificial turf contribute to head injuries?

BACKGROUND: A number of high-profile professional football players have suffered career-ending concussions. The purpose of this article is to test the surfaces used by a professional team to determine their impact-attenuating properties. METHODS: An accelerometer was dropped from a height of 48 inches onto three different playing fields in the St. Louis area: an indoor artificial turf practice field, a grass outdoor practice field, and the artificial turf field at a domed stadium. The accelerometer was dropped 20 times from a height of 48 inches onto each surface. RESULTS: Statistical analysis of the peak Gs for impacts onto each surface indicate all three are statistically different. The artificial surface of the domed stadium was the hardest surface, with an average peak acceleration of 261 Gs compared with 183 Gs for the indoor artificial turf practice field and 246 Gs for the outdoor grass field. CONCLUSION: The surface used to play league games has the least impact attenuation of any field tested and may contribute to the high incidence of concussion in football players.