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Background: Current clinical practice guidelines (CPG) recommend periodic pressure redistribution (PR) to alter sitting pressure and reduce the risk of developing pressure injuries (PI). Individuals who have strength and trunk stability are asked to perform PR such as wheelies, leaning laterally, and forward-leaning to minimize the duration of pressure acting on the same region of the body., Objective: Our long-term objective is to build upon previous research and development to create a more effective device for improving PR training and adherence to CPG among manual wheelchair users (MWU). Through this study, we employed a participatory action design and engineering (PADE) approach in developing the hardware and user interface to increase the likelihood of eventually yielding a device effective for both MWU and clinicians., Participants: Focus Groups : Ten clinicians - 6 physical therapists, 3 occupational therapists, and one registered nurse, and 10 MWU with spinal cord injuries (SCI) who reported using their wheelchairs 40-80 h per week. Five-Day Assessment : Five male MWU with SCI who had been wheelchair users for 18.5 ± 16.2 years. Four-Week Investigation : The 7 participants with SCI were 5 males and 2 females, who had been wheelchair users for 24.7 ± 17.0 years., Methods: A PADE approach was used to improve upon a manual wheelchair virtual coaching system for people with SCI. The system comprises a seat support instrumented with force sensors, software algorithms to detect PR, and a smart phone app for user interface. The methods included three stages: multiple focus groups, a five-day evaluation phase with participants using their own wheelchairs in their homes and communities, and a 4-week assessment with improvements made based on the 5-day results by users with their own wheelchairs in their homes and communities., Results: The focus groups yielded guidance for ergonomics, user interface, charging frequency, and key dimensions and mass. The 5-day study identified mechanical, electrical, and connectivity challenges, which were resolved before the 4-week study. The 4-week trial suggested that participants performed PR less frequently than clinically recommended and provided an indication of the types of maneuvers that they performed., Conclusion: A prototype manual wheelchair virtual coaching system was developed using a PADE process. The system was able to detect and record PR in home and community environments. Following improvements identified in this study, a future version will be tested with additional users to determine whether it can improve adherence to PR guidance.

Objective: The purpose of this study was to compare trunk mechanics, distance covered, and average instantaneous velocity and acceleration recorded with caregivers performing transfer tasks using a research mannequin with both a prototype robotic assisted transfer device (RATD) and a mobile floor lift., Design: Cross-Sectional., Setting: Biomechanics Lab and Human Engineering Research Laboratories., Participants: Caregivers ( N  = 21)., Intervention: Robotic Assisted Transfer Device., Outcome Measures: Range of flexion-extension, lateral bend, and axial rotation; distance covered; average instantaneous velocity and acceleration., Results: Caregivers performing transfers using the RATD as compared to when using the moble floor lift reported significantly smaller range of trunk flexion-extension, lateral bending, and axial rotation, and reported lower pelvic based distance covered and slower average instantaneous velocity and acceleration (P < 0.001)., Conclusion: The design and usability of a RATD indicates design driven mobility advantages over clinical standard mobile floor lifts due to its ability to expand the workspace while further reducing risk factors for low back pain. While the concept is promising, further testing is required to address limitations and confirm the concept for clinical applications.

Background: Assistive robotic manipulators (ARMs) have been developed to provide enhanced assistance and independence in performance of daily activities among people with spinal cord injury when a caregiver is not on site. However, the current commercial ARM user interfaces (UIs) may be difficult to learn and control. A touchscreen mobile UI was developed to overcome these challenges. Objective: The object of this study was to evaluate the performance between 2 ARM UIs, touchscreen and the original joystick, using an ARM evaluation tool (ARMET). Methods: This is a pilot study of people with upper extremity impairments ( N = 8). Participants were trained on 2 UIs, and then they chose one to use when performing 3 tasks on the ARMET: flipping a toggle switch, pushing down a door handle, and turning a knob. Task completion time, mean velocity, and open interviews were the main outcome measurements. Results: Among 8 novice participants, 7 chose the touchscreen UI and 1 chose the joystick UI. All participants could complete the ARMET tasks independently. Use of the touchscreen UI resulted in enhanced ARMET performance (higher mean moving speed and faster task completion). Conclusions: Mobile ARM UIs demonstrated easier learning experience, less physical effort, and better ARMET performance. The improved performance, the accessibility, and lower physical effort suggested that the touchscreen UI might be an efficient tool for the ARM users.

Objective: The overall objective of this project was to identify consumers' opinions of their needs and wants related to assistive technology (AT) in a systematic and quantitative manner via a questionnaire that can be used to validate existing and establish new research priorities. Methods: This pilot study describes questionnaire development, online implementation, and revisions considered to the questionnaire in preparation for conducting a nationwide survey. Data from a sample ( N = 112) are presented. The pilot study was critical to refine the questions and ensure that meaningful information was being collected. Results: It was identified that revisions were warranted to provide more structure and allow for consumers to prioritize AT research efforts. Conclusion: The questionnaire results, although positively in favor of many of the technologies presented, are inconclusive to identify generalizable research priorities, thus expansion to a nationwide population is warranted., Competing Interests: The authors report no conflicts of interest.

Assistive technology is essential to people with spinal cord injuries (SCI) for living and participating in their communities. However, many people with SCI do not have access to adequate assistive technology and qualified services. The World Health Organization (WHO) is addressing this need through the Global Cooperation on Assistive Technology (GATE). The GATE initiative is focused on improving access to high-quality affordable AT world-wide. GATE working to meet the AT sector needs in response to the call by WHO to increase access to essential, high-quality, safe, effective and affordable medical devices, which is one of the six WHO leadership priorities.

Objectives: To investigate correlations between power seat functions (PSFs) usage and wheelchair discomfort., Design: Quasi-experimental design: Time series design., Setting: In-home trial in participants' home/community., Participants: Thirteen power wheelchair users who independently used power wheelchairs equipped with PSFs as their primary means of mobility., Main Outcome Measures: PSF usage variables include the frequency of performing repositioning and using PSFs (tilt, recline, legrests and seat elevation), wheelchair occupancy, and driving distance. The Tool for Assessing Wheelchair disComfort (TAWC) were used to evaluate general discomfort and discomfort intensity., Results: Spearman correlation coefficient showed that the frequency of using tilt, recline, and legrest is significantly correlated with discomfort intensity. Multiple regression analysis with backward stepwise indicated that these functions can explain 43.8% of the variance (R2 = .438, F(3,33) = 8.588, P < 0.01) in the discomfort intensity score. The best-first decision tree shows that the frequency of using the legrest function was the top node, followed by recline and tilt functions. The overall accuracy of prediction with ten-fold cross validation for discomfort intensity was 79.4%., Conclusions: For people who used power wheelchairs equipped with PSFs, correlation analysis and regression modeling provided evidence from the quantitative data that increasing the frequency of using PSFs may decrease wheelchair discomfort. Future studies should include interventions to encourage people to use their PSFs appropriately.

Objective: To investigate the frequency and types of wheelchair repairs and associated adverse consequences., Design: Convenience cross-sectional sample survey., Setting: Nine Spinal Cord Injury Model Systems Centers., Participants: People with spinal cord injury who use a wheelchair >40h/wk (N=591)., Interventions: Not applicable., Main Outcome Measures: Number of repairs needed and resulting adverse consequences, number and types of repairs completed, and location where main repair was completed in the previous 6 months., Results: There were 591 participants responded to the survey, 63.8% (377/591) of them needed ≥1 repair; of these, 27.6% (104/377) experienced ≥1 adverse consequence, including 18.2% (69/377) individuals who were stranded. Of those who needed repairs, 6.9% did not have them completed (26/377). Repairs completed on the wheels and casters were the most frequent repair to manual wheelchairs, whereas repairs to the electrical and power and control systems were the most frequent type of repair on power wheelchairs. Forty percent (79/201) of manual wheelchair users reported completing repairs at home themselves compared with 14% (21/150) of power wheelchair users. Twelve percent of the variance in the odds of facing an adverse consequence because of a wheelchair breakdown can be described as a function of occupation, funding source, and type of wheelchair., Conclusions: Wheelchair repairs are highly prevalent. There are differences in types of repairs and who completes the repairs based on the type of wheelchair. Wheelchair breakdowns result in adverse consequences for users, and there is a deficit between repairs needed and those completed, highlighting the need for interventions that address these problems., (Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the immediate effects of transfer training based on the Transfer Assessment Instrument (TAI) on the upper limb biomechanics during transfers., Design: Pre-post intervention., Setting: Biomechanics laboratory., Participants: Full-time manual wheelchair users (N=24) performed 5 transfers to a level height bench, while their natural transfer skills were scored using the TAI, and their biomechanical data were recorded., Intervention: Participants with 2 or more component skill deficits were invited to return to receive personalized transfer training., Main Outcome Measures: TAI part 1 summary scores and biomechanical variables calculated at the shoulder, elbow, and wrist joints were compared before and immediately after transfer training., Results: Sixteen of the 24 manual wheelchair users met the criteria for training, and 11 manual wheelchair users came back for the revisit. Their TAI part 1 summary scores improved from 6.31±.98 to 9.92±.25. They had significantly smaller elbow range of motion, shoulder resultant moment, and rates of rise of elbow and wrist resultant forces on their trailing side during transfers after training (P<.05). On the leading side, shoulder maximum internal rotation and elevation angles, and shoulder resultant moments and rates of rise of shoulder resultant force and moment decreased after training (P<.04)., Conclusions: The TAI-based training showed short-term beneficial biomechanical effects on wheelchair users' upper limbs, such as better shoulder positioning and lower joint loadings. If the skills are practiced longer-term, they may help protect the upper limbs from developing pain and injuries., (Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To develop and evaluate energy expenditure (EE) estimation models for a physical activity monitoring system (PAMS) in manual wheelchair users with spinal cord injury (SCI)., Design: Cross-sectional study., Setting: University-based laboratory environment, a semistructured environment at the National Veterans Wheelchair Games, and the participants' home environments., Participants: Volunteer sample of manual wheelchair users with SCI (N=45)., Intervention: Participants were asked to perform 10 physical activities (PAs) of various intensities from a list. The PAMS consists of a gyroscope-based wheel rotation monitor (G-WRM) and an accelerometer device worn on the upper arm or on the wrist. Criterion EE using a portable metabolic cart and raw sensor data from PAMS were collected during each of these activities., Main Outcome Measures: Estimated EE using custom models for manual wheelchair users based on either the G-WRM and arm accelerometer (PAMS-Arm) or the G-WRM and wrist accelerometer (PAMS-Wrist)., Results: EE estimation performance for the PAMS-Arm (average error ± SD: -9.82%±37.03%) and PAMS-Wrist (-5.65%±32.61%) on the validation dataset indicated that both PAMS-Arm and PAMS-Wrist were able to estimate EE for a range of PAs with <10% error. Moderate to high intraclass correlation coefficients (ICCs) indicated that the EE estimated by PAMS-Arm (ICC3,1=.82, P<.05) and PAMS-Wrist (ICC3,1=.89, P<.05) are consistent with the criterion EE., Conclusions: Availability of PA monitors can assist wheelchair users to track PA levels, leading toward a healthier lifestyle. The new models we developed can estimate PA levels in manual wheelchair users with SCI in laboratory and community settings., (Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Study Design: Repeated measures design., Objective: This study compared the upper extremity (UE) joint kinetics between three transfer techniques., Setting: Research laboratory., Methods: Twenty individuals with spinal cord injury performed three transfer techniques from their wheelchair to a level tub bench. Two of the techniques involved a head-hips method with leading hand position close (HH-I) and far (HH-A) from the body, and the third technique with the trunk upright (TU) and hand far from body. Motion analysis equipment recorded upper body movements and force sensors recorded their hand and feet reaction forces during the transfers., Results: Several significant differences were found between HH-A and HH-I and TU and HH-I transfers indicating that hand placement was a key factor influencing the UE joint kinetics. Peak resultant hand, elbow, and shoulder joint forces were significantly higher for the HH-A and TU techniques at the trailing arm (P < 0.036) and lower at the leading arm (P < 0.021), compared to the HH-I technique., Conclusion: Always trailing with the same arm if using HH-A or TU could predispose that arm to overuse related pain and injuries. Technique training should focus on initial hand placement close to the body followed by the amount of trunk flexion needed to facilitate movement.

Physical activity monitors are increasingly used to help the general population lead a healthy lifestyle by keeping track of their daily physical activity (PA) and energy expenditure (EE). However, none of the commercially available activity monitors can accurately estimate PA and EE in people who use wheelchairs as their primary means of mobility. Researchers have recently developed custom EE prediction models for manual wheelchair users (MWUs) with spinal cord injuries (SCIs) based on a commercial activity monitor--the SenseWear armband. This study evaluated the performance of two custom EE prediction models, including a general model and a set of activity-specific models among 45 MWUs with SCI. The estimated EE was obtained by using the two custom models and the default manufacturer's model, and it was compared with the gold standard measured by the K4b2 portable metabolic cart. The general, activity-specific, and default models had a mean signed percent error (mean +/- standard deviation) of -2.8 +/- 26.1%, -4.8 +/- 25.4%, and -39.6 +/- 37.8%, respectively. The intraclass correlation coefficient was 0.86 (95% confidence interval [CI] = 0.82 to 0.89) for the general model, 0.83 (95% CI = 0.79 to 0.87) for the activity-specific model, and 0.62 (95% CI = 0.16 to 0.81) for the default model. The custom models for the SenseWear armband significantly improved the EE estimation accuracy for MWUs with SCI.

Study Design: Validation., Objectives: The primary aim of this study was to develop and evaluate activity classification algorithms for a multisensor-based SenseWear (SW) activity monitor that can recognize wheelchair-related activities performed by manual wheelchair users (MWUs) with spinal cord injury (SCI). The secondary aim was to evaluate how the accuracy in activity classification affects the estimation of energy expenditure (EE) in MWUs with SCI., Setting: University-based laboratory., Methods: Forty-five MWUs with SCI wore a SW on their upper arm and participated in resting, wheelchair propulsion, arm-ergometery and deskwork activities. The investigators annotated the start and end of each activity trial while the SW collected multisensor data and a portable metabolic cart collected criterion EE. Three methods including linear discriminant analysis, quadratic discriminant analysis (QDA), and Naïve Bayes (NB) were used to develop classification algorithms for four activities based on the training data set from 36 subjects., Results: The classification accuracy was 96.3% for QDA and 94.8% for NB when the classification algorithms were tested on the validation data set from nine subjects. The average EE estimation errors using the activity-specific EE prediction model were 5.3±21.5% and 4.6±22.8% when the QDA and NB classification algorithms were applied, respectively, as opposed to 4.9±20.7% when 100% classification accuracy was assumed., Conclusion: The high classification accuracy and low EE estimation errors suggest that the SW can be used by researchers and clinicians to classify and estimate the EE for the four activities tested in this study among MWUs with SCI.

Objective: To develop and evaluate new energy expenditure (EE) prediction models for manual wheelchair users (MWUs) with spinal cord injury (SCI) based on a commercially available multisensor-based activity monitor., Design: Cross-sectional., Setting: Laboratory., Participants: Volunteer sample of MWUs with SCI (N=45)., Intervention: Subjects were asked to perform 4 activities including resting, wheelchair propulsion, arm-ergometer exercise, and deskwork. Criterion EE using a metabolic cart and raw sensor data from a multisensor activity monitor was collected during each of these activities., Main Outcome Measures: Two new EE prediction models including a general model and an activity-specific model were developed using enhanced all-possible regressions on 36 MWUs and tested on the remaining 9 MWUs., Results: The activity-specific and general EE prediction models estimated the EE significantly better than the manufacturer's model. The average EE estimation error using the manufacturer's model and the new general and activity-specific models for all activities combined was -55.31% (overestimation), 2.30% (underestimation), and 4.85%, respectively. The average EE estimation error using the manufacturer's model, the new general model, and activity-specific models for various activities varied from -19.10% to -89.85%, -18.13% to 25.13%, and -4.31% to 9.93%, respectively., Conclusions: The predictors for the new models were based on accelerometer and demographic variables, indicating that movement and subject parameters were necessary in estimating the EE. The results indicate that the multisensor activity monitor with new prediction models can be used to estimate EE in MWUs with SCI during wheelchair-related activities mentioned in this study., (Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: The objective of this study was to investigate differences in shoulder, elbow and hand kinetics while performing three different SPTs that varied in terms of hand and trunk positioning., Methods: Fourteen unimpaired individuals (8 male and 6 female) performed three variations of sitting pivot transfers in a random order from a wheelchair to a level tub bench. Two transfers involved a forward flexed trunk (head-hips technique) and the third with the trunk remaining upright. The two transfers involving a head hips technique were performed with two different leading hand initial positions. Motion analysis equipment recorded upper body movements and force sensors recorded hand reaction forces. Shoulder and elbow joint and hand kinetics were computed for the lift phase of the transfer., Findings: Transferring using either of the head hips techniques compared to the trunk upright style of transferring resulted in reduced superior forces at the shoulder (P<0.002), elbow (P<0.004) and hand (P<0.013). There was a significant increase in the medial forces in the leading elbow (P=0.049) for both head hip transfers and the trailing hand for the head hip technique with the arm further away from the body (P<0.028). The head hip techniques resulted in higher shoulder external rotation, flexion and extension moments compared to the trunk upright technique (P<0.021)., Interpretation: Varying the hand placement and trunk positioning during transfers changes the load distribution across all upper limb joints. The results of this study may be useful for determining a technique that helps preserve upper limb function overtime., (Published by Elsevier Ltd.)

Objective: To examine quality-of-life (QOL) factors and change in mobility in individuals with traumatic spinal cord injury (SCI) 1 year after injury., Design: Retrospective case study of National SCI Database data., Setting: SCI Model Systems (SCIMS) sites (N=18)., Participants: Subjects (N=1826; age >18y) who presented to an SCIMS site after traumatic SCI between June 2004 and July 2009 and returned for 1-year follow-up. All subjects had FIM mobility data for both assessments., Interventions: Not applicable., Main Outcome Measures: Assessment of impairment based on Lower-Extremity Motor Score. Assessment of QOL based on Craig Handicap Assessment and Reporting Technique, Patient Health Questionnaire, Satisfaction With Life Scale, Self-perceived Health Status, and pain severity scores., Results: Of the sample, 55 individuals transitioned from walking to wheelchair use within 1 year of discharge. This group had the highest number of individuals from minority groups (52.8%) and the lowest employment rate (7.3%). Compared with individuals who transitioned from wheelchair use to walking or maintained wheelchair use or ambulation, the walking-to-wheelchair transition group had significantly lower QOL scores (P<.01), including higher depression (P<.01) and higher pain severity (P<.001)., Conclusions: Individuals with SCI who transitioned from walking at discharge to wheelchair use within 1 year had low QOL factors, including high pain and depression scores. Rehabilitation professionals should consider encouraging marginal ambulators to work toward functional independence from a wheelchair, rather than primary ambulation during acute inpatient rehabilitation., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

This study describes a new custom measurement system designed to investigate the biomechanics of sitting-pivot wheelchair transfers and assesses the reliability of selected biomechanical variables. Variables assessed include horizontal and vertical reaction forces underneath both hands and three-dimensional trunk, shoulder, and elbow range of motion. We examined the reliability of these measures between 5 consecutive transfer trials for 5 subjects with spinal cord injury and 12 nondisabled subjects while they performed a self-selected sitting pivot transfer from a wheelchair to a level bench. A majority of the biomechanical variables demonstrated moderate to excellent reliability (r > 0.6). The transfer measurement system recorded reliable and valid biomechanical data for future studies of sitting-pivot wheelchair transfers.We recommend a minimum of five transfer trials to obtain a reliable measure of transfer technique for future studies.

Technology plays a critical role in promoting well-being, activity, and participation for individuals with spinal cord injury (SCI). As technology has improved, so has the realm of possibilities open to people with SCI. School, work, travel, and leisure activities are all facilitated by technology. Advances in materials have made wheelchairs lighter, and developments in design have made wheelchairs that fit individual needs. Software has made computer interfaces adaptive and in some case intelligent, through learning the user's behavior and optimizing its structure. As participatory action design and aware systems take greater hold, transformational change is likely to take place in the technology available to people with SCI.

Unlabelled: McClure LA, Boninger ML, Oyster ML, Williams S, Houlihan B, Lieberman JA, Cooper RA. Wheelchair repairs, breakdown, and adverse consequences for people with traumatic spinal cord injury., Objectives: To investigate the frequency of repairs that occurred in a 6-month period and the consequences of breakdowns on wheelchair users living with spinal cord injuries (SCIs), and to determine whether certain wheelchair and subject characteristics are associated with an increased number of repairs and adverse consequences., Design: Convenience sample survey., Setting: Sixteen Model Spinal Cord Injury Systems Centers that are part of the national database funded through the Department of Education, National Institute on Disability and Rehabilitation Research., Participants: People with SCI who use a wheelchair for more than 40h/wk (N=2213)., Intervention: Not applicable., Main Outcome Measures: The frequency of wheelchair repairs and occurrence of adverse consequences caused by a wheelchair breakdown in a 6-month period., Results: Within a 6-month period, 44.8% of full-time wheelchair users completed a repair, and 8.7% had an adverse consequence occur. People who use power wheelchairs required significantly more repairs (P<.001), and adverse consequences occurred more frequently (P<.001) compared with manual wheelchair users. The presence of power seat functions, and a person's occupational status or sex did not influence the number of repairs or adverse consequences., Conclusions: Frequent repairs and breakdown can negatively impact a person's life by decreasing community participation and threatening health and safety. Mandatory compliance with the American National Standards Institute and the Rehabilitation Engineering and Assistive Technology Society of North America standards, changes in insurance reimbursement policy, and patient and clinician education are necessary to reduce the number of repairs and adverse consequences that occur.

Objectives: To classify propulsion patterns over surfaces encountered in the natural environment during start-up and compare selected biomechanical variables between pattern types., Design: Case series., Setting: National Veterans Wheelchair Games, Minneapolis, MN, 2005., Participants: Manual wheelchair users (N=29)., Intervention: Subjects pushed their wheelchairs from a resting position over high-pile carpet, over linoleum, and up a ramp with a 5 degrees incline while propulsion kinematics and kinetics were recorded with a motion capture system and an instrumented wheel., Main Outcome Measures: Three raters classified the first 3 strokes as 1 of 4 types on each surface: arc, semicircular (SC), single looping over propulsion (SL), and double looping over propulsion (DL). The Fisher exact test was used to assess pattern changes between strokes and surface type. A multiple analysis of variance test was used to compare peak and average resultant force and moment about the hub, average wheel velocity, stroke frequency, contact angle, and distance traveled between stroke patterns., Results: SL was the most common pattern used during start-up propulsion (44.9%), followed by arc (35.9%), DL (14.1%), and SC (5.1%). Subjects who dropped their hands below the rim during recovery achieved faster velocities and covered greater distances (.016< or =P< or =.075) during start-up on linoleum and carpet and applied more force during start-up on the ramp compared with those who used an arc pattern (P=.066)., Conclusions: Classifying propulsion patterns is a difficult task that should use multiple raters. In addition, propulsion patterns change during start-up, with an arc pattern most prevalent initially. The biomechanical findings in this study agree with current clinical guidelines that recommend training users to drop the hand below the pushrim during recovery.

Background: The objective of this study was to examine how surface electrical stimulation of trunk musculature influences the kinematic, kinetic, and metabolic characteristics, as well as shoulder muscle activity, during wheelchair propulsion., Methods: Eleven participants with spinal cord injury propelled their own wheelchairs on a dynamometer at a speed of 1.3 m/s for three 5-minute trials. During a propulsion trial, 1 of 3 stimulation levels (HIGH, LOW, and OFF) was randomly applied to the participant's abdominal and back muscle groups with a surface functional electrical stimulation device. Propulsion kinetics, trunk kinematics, metabolic responses, and surface electromyographic (EMG) activity of 6 shoulder muscles were collected synchronously. Kinetic, kinematic, and EMG variables were recorded during 3 time intervals (30 seconds each) within a 5-minute trial. Metabolic variables were recorded through the entire 5-minute trial., Results: Participants with HIGH stimulation increased their gross mechanical efficiency (P=.05) during wheelchair propulsion. No differences were found in shoulder EMG activity, energy expenditure, and trunk motion between stimulation levels., Conclusion: Functional electrical stimulation on the trunk musculature has potential advantages in helping manual wheelchair users with spinal cord injury improve propulsion efficiency without placing additional demands on shoulder musculature.

This study's main objective was to determine if upper-limb (UL) muscular demand was reduced when individuals with a spinal cord injury (SCI) performed a sitting pivot transfer (SPT) in the preferred direction compared with that in a nonpreferred direction. Fourteen individuals (mean +/- standard deviation age 47.0 +/- 8.3 yr, height 1.80 +/- 0.08 m, and weight 75.3 +/- 11.3 kg) with SCI levels ranging from the sixth cervical to first sacral vertebra levels volunteered to participate in this study during the 2008 National Disabled Veterans Winter Sports Clinic. Surface electromyography (EMG) was used to record activity of the biceps, triceps, deltoid, pectoralis major, trapezius, and latissimus dorsi bilaterally during SPTs. These transfers were performed in each of the preferred and nonpreferred directions from the individuals' wheelchairs to a padded tub bench of even height. To quantify electromyographic muscular utilization ratio (MUR(EMG)), we normalized EMG data recorded during the transfer tasks to values obtained during static maximum voluntary contraction and then multiplied this ratio by 100 to obtain a percentage MUR(EMG) (%MUR(EMG)). The overall peak %MUR(EMG) and the area under the %MUR(EMG) curve were selected as primary outcome measures. Similar peak %MUR(EMGs) were found between the preferred and nonpreferred transfer directions for all muscles from which data were recorded (p = 0.053 to 0.961). The peak %MUR(EMGs) were also found to be similar between the leading and trailing ULs during the transfers in all muscles from which data were recorded (p = 0.125 to 0.838), except for the anterior deltoid, which was found to be solicited the most in the trailing UL (p = 0.008). Comparable areas under the %MUR(EMG) curves were calculated between the preferred and nonpreferred transfer directions for all muscles (p = 0.289 to 0.678) and between the leading and trailing ULs (p = 0.104 to 0.946). These results indicate that direction preference expressed by individuals with SCI when transferring between seats of even height is not explained by relative muscular demand differences.

Objectives: To describe a standard clinical protocol for the objective assessment of manual wheelchair propulsion; to establish preliminary values for temporal and kinetic parameters derived from the protocol; and to develop graphical references and a proposed application process for use by clinicians., Design: Case series., Setting: Six research institutions that collect kinetic wheelchair propulsion data and contribute that data to an international data pool., Participants: Subjects with spinal cord injury (N=128)., Interventions: Subjects propelled a wheelchair from a stationary position to a self-selected velocity across a hard tile surface, a low pile carpet, and up an Americans with Disabilities Act-compliant ramp. Unilateral kinetic data were obtained from subjects using a force and moment sensing pushrim., Main Outcome Measures: Differences in self-selected velocity, peak resultant force, push frequency, and stroke length across all surfaces, relationship between (1) weight-normalized peak resultant force and self-selected velocity and (2) push frequency and self-selected velocity., Results: Graphical references were generated for potential clinical use based on the relation between body weight-normalized peak resultant force, push frequency, and velocity. Self-selected velocity decreased (ramp < carpet < tile), peak resultant forces increased (ramp > carpet > tile), and push frequency and stroke length remained unchanged when compared across the different surfaces. Weight-normalized peak resultant force was a significant predictor of velocity on tile and ramp. Push frequency was a significant predictor of velocity on tile, carpet, and ramp., Conclusions: We present preliminary data generated from a clinically practical manual wheelchair propulsion evaluation protocol and we describe a proposed method for clinicians to objectively evaluate manual wheelchair propulsion.

Manual wheelchair users are subjected to whole-body vibrations (WBV) on a regular basis as they traverse obstacles and uneven surfaces. One way users could protect themselves from secondary injuries related to WBV is by using a suspension manual wheelchair. This study investigated the ability of suspension manual wheelchairs to reduce seat accelerations during curb descents of various heights (5, 10, and 15 cm). Sixteen manual wheelchairs (four suspension, four folding, four rigid, and four rigid titanium) were tested. Suspension wheelchairs transmitted significantly lower peak seat accelerations than folding wheelchairs during the 5 cm curb descents (p = 0.048) and significantly lower frequency-weighted peak seat accelerations during the 5 and 10 cm curb descents (p = 0.03 for both heights). However, when the suspension wheelchair Quickie XTR (Sunrise Medical; Carlsbad, California) was removed from the analysis, the suspension wheelchairs were not significantly different from the nonsuspension wheelchairs. When weight was considered, the suspension wheelchairs had significantly lower peak seat accelerations than the lighter rigid wheelchairs during 5 cm curb descents (p = 0.047). While suspension manual wheelchairs offer some reduction in WBV during curb descents, their limitations should be considered when a wheelchair is selected for everyday use.

Individuals with multiple sclerosis (MS) report decreased satisfaction with their mobility devices compared with individuals with spinal cord injuries (SCIs). This study (1) investigated the demographic differences between veterans with MS (V-MS) and veterans with SCI (V-SCI) who were issued a wheelchair by the Veterans Health Administration (VHA) and (2) described differences in mobility device prescription. We merged two VHA databases to obtain demographic and wheelchair information for all V-MS and V-SCI in 2000 and 2001. Descriptive information for issued wheelchairs was available for 2,154 V-MS and V-SCI. We found that V-MS were significantly less likely to receive higher quality wheelchairs (manual or power) compared with V-SCI (p < 0.001). The disparity in VHA wheelchair prescription between these two groups indicates a need for further research regarding the assistive device prescription process in these populations.

A multisite collaborative study is being conducted on the association between propulsion biomechanics and upper-limb injuries. This substudy compared subject characteristics and pushrim kinetics across three sites and identified early on in the main study any differences that could affect interpretation of the findings or data pooling. A total of 42 manual wheelchair users with paraplegia (14 from each site) performed 0.9 m/s and 1.8 m/s steady state propulsion trials and an acceleration-brake-coastdown trial on a wheelchair dynamometer while propulsion forces and moment about the hub were measured with a SmartWheel. Significant differences between two sites were found in peak and average resultant force (p < 0.05), peak and average moment at the slower steady state speed (p < 0.005), and peak and average torque at the faster steady state speed (p = 0.06). Subjects at the site with significantly lower forces and torques had a slower deceleration rate during coastdown compared with the subjects at the other two sites (p < 0.001). These results imply that rolling resistance is lower at one of the sites and likely due to differences in dynamometer properties. A mechanical method was used to site-normalize the data and enable data pooling for future analyses.

The INDEPENDENCE 3000 IBOT Transporter (IBOT), as an electronically stabilized mobility device for people with disabilities. The purpose of this study was to gain experience with the IBOT at home and in the community using an expert wheelchair user, who used the device as his primary mobility device for 1 week. This case report is based upon observations by trained clinicians, and a diary recorded by the primary author a male manual wheelchair user with traumatic spinal cord injury at the T7/8 level. The subject was 41 years of age and 21 years post SCI at the time of the study. The participant was employed and lived in a ranch style accessible home. The subject used the devices to perform a variety of activities including holding eye-level discussions with colleagues and shopping by balancing on two wheels, going up and down steep ramps, traversing outdoor surfaces (e.g., grass, dirt trails) and climbing curbs. The balance and four-wheel drive functions were helpful and worked well. The IBOT was somewhat difficult to control in standard function. The seat height was too high for most tables and desks encountered, and transfers were notably more difficult than with other wheelchairs. It was difficult to use the IBOT in the bathroom, and the subject preferred to use his personal wheelchairs for transfers into the shower. The IBOT was a functional mobility device, its greatest strengths are outdoors and in circumstances where there is space to use balance function.

Over 50 percent of manual wheelchair users with spinal cord injury (SCI) are likely to develop upper-limb pain and injury. The majority of studies related to pain have implicated wheelchair propulsion as a cause. This paper draws from a large multisite trial and a long-standing research program to make specific recommendations related to wheelchair propulsion that may decrease the risk of upper-limb injury. The studies include over 60 subjects over 1 yr after a traumatic SCI below the second thoracic level. Specific aspects of the propulsive stroke that may relate to injury include cadence, magnitude of force, and the pattern of the hand during the nonpropulsive part of the stroke. Lower peak forces, slower cadence, and a circular propulsive stroke in which the hand falls below the pushrim during recovery may help prevent injury. In addition, wheelchair users should use the lightest weight adjustable wheelchair possible. Future work should include interventional trials and larger studies that allow for more complex statistical models that can further detail the relationship between wheelchair propulsion, user characteristics, and upper-limb injuries.

Introduction: Manual wheelchair users have been found to be at risk for secondary upper extremity injuries., Purpose: The primary goal of this study was to compare shoulder strength and muscle imbalance of individuals with paraplegia to case-wise matched unimpaired controls (UC). A secondary goal was to evaluate the impact of age and neurologic level of injury (NLI) on weight-normalized strength (WNS)., Methods: The SCI group (n = 28) and the UC group (n = 28) completed bilateral shoulder isokinetic strength testing in the sagittal, frontal, and horizontal plane at 60 degrees/second using the BioDex system. Strength ratios, an indicator of muscle imbalance, were also calculated., Results: No significant difference was seen in shoulder strength or strength ratios between the SCI group and the UC group. However, NLI was significantly related to WNS on several planes in the SCI group. Therefore, we dichotomized the SCI group into equal groups based on an NLI. The Low-SCI group was significantly stronger than the High-SCI group in most planes (P < 0.05). The High-SCI group was significantly weaker than the UC in extension (P < 0.01) and a trend (P < 0.01) was seen in flexion, abduction, and external rotation. The Low-SCI group was significantly stronger in abduction than the UC., Conclusion: WNS at the shoulder correlated with NLI. It is likely that this is related to contributions of the trunk and abdominal muscles during testing, since proximal trunk strength aids in generating forces distally. This study and others of strength in individuals with paraplegia may overestimate shoulder strength.

Background/objective: Previous investigations have identified muscular imbalance in the shoulder as a source of pain and injury in manual wheelchair users. Our aim was to determine whether a correlation exists between strength and pushrim biomechanical variables including: tangential (motive) force (Ft), radial force (Fr), axial force (Fz), total (resultant) force (FR), fraction of effective force (FEF), and cadence., Methods: Peak isokinetic shoulder strength (flexion [FLX], extension [EXT], abduction [ABD], adduction [ADD], internal rotation [IR], and external rotation [ER]) was tested in 22 manual wheelchair users with a BioDex system for 5 repetitions at 60 degrees/s. Subjects then propelled their own manual wheelchair at 2 speeds, 0.9 m/s (2 mph) and 1.8 m/s (4 mph), for 20 seconds, during which kinematic (OPTOTRAK) and kinetic (SMARTWHEEL) data were collected. Peak isokinetic forces in the cardinal planes were correlated with pushrim biomechanical variables., Results: All peak torque strength variables correlated significantly (P < or = 0.05) with Ft, Fr, and FR, but were not significantly correlated with Fz, FEF, or cadence. Finally, there were no relationships found between muscle strength ratios (for example, FLX/EXT) and Ft, Fr, FR, Fz, or FEF., Conclusion: There was a correlation between strength and force imparted to the pushrim among wheelchair users; however, there was no correlation found in wheelchair propulsion or muscle imbalance. Clinicians should be aware of this, and approach strength training and training in wheelchair propulsion techniques separately.

Objective: To investigate factors related to the wheelchair, impairment, and environment that affect perception of participation of persons with spinal cord injury (SCI) in activities performed in 3 settings: in the home, in the community, and during transportation., Design: Cross-sectional study., Setting: Research centers and a specialized assistive technology (AT) clinic in Pittsburgh (Pitt). Research centers and community-based rehabilitation technology suppliers in Saint Louis (SL)., Participants: Seventy wheelchair users with SCI., Interventions: Subjects from Pitt and SL completed a written survey of AT usage in daily activities., Main Outcome Measures: Subjects were asked 5 questions within each setting (home, community, transportation) related to their perceived reason for functional limitations., Results: The wheelchair was the most commonly cited factor limiting participation, followed by physical impairment and physical environment. Twenty-one percent of subjects with paraplegia reported pain as a limiting factor for their transportation use, significantly more (P=.047) than subjects with tetraplegia (3%). A trend (P=.099) was seen toward a higher percentage of subjects with tetraplegia (tetraplegia, 7%; paraplegia, 3%) reporting lack of equipment as a limiting factor for use of transportation. Differences were also seen across sites., Conclusions: The wheelchair was the most commonly cited limiting factor, followed by physical impairment and physical environment. The wheelchair is the most important mobility device used by persons with SCI and the one that users most associate with barriers.

Objectives: To determine if a standard of care for wheelchair provision exists within the participating centers and if there is disparity in wheelchair customizability among the study sample., Design: Convenience sample survey., Setting: Thirteen Model Spinal Cord Injury Systems that provide comprehensive rehabilitation for people with traumatic spinal cord injury (SCI) and that are part of the national database funded through the US Department of Education., Participants: A total of 412 people with SCI who use wheelchairs over 40 hours a week., Intervention: Survey information was obtained from subjects via telephone and in-person interviews and from the national database. Collected information included age, race, education, level of injury, and wheelchair funding source., Main Outcome Measures: Number and type (manual or power) of wheelchairs. Wheelchair customizability as defined by design features (eg, adjustable axle position, programmable controls)., Results: Ninety-seven percent of manual wheelchair users and 54% of power wheelchair users had customizable wheelchairs. No power wheelchair user received a wheelchair without programmable controls. Minorities with low socioeconomic backgrounds (low income, Medicaid/Medicare recipients, less educated) were more likely to have standard manual and standard programmable power wheelchairs. Older subjects were also more likely to have standard programmable power wheelchairs., Conclusions: The standard of care for manual wheelchair users with SCI is a lightweight and customizable wheelchair. The standard of care for power wheelchairs users has programmable controls. Unfortunately, socioeconomically disadvantaged people were less likely to receive customizable wheelchairs.

Objective: To investigate the relation between median and ulnar nerve health and wrist kinematics in wheelchair users., Design: Case series., Setting: Biomechanics laboratory and electrodiagnostic laboratory at a Veterans Health Administration medical center and a university hospital, respectively., Participants: Thirty-five people with spinal cord injury who use manual wheelchairs., Intervention: Subjects propelled their own wheelchair on a dynamometer at 0.9 and 1.8m/s. Bilateral biomechanic data were obtained by using force and moment sensing pushrims and a kinematic system. Bilateral median and ulnar nerve conduction studies were also completed., Main Outcome Measures: Wrist flexion, extension, radial and ulnar deviation peaks, and ranges of motion (ROMs) as related to median and ulnar motor and sensory amplitudes. A secondary analysis included peak pushrim forces and moments and stroke frequency., Results: There was a significant, positive correlation between flexion and extension ROM and both ulnar motor amplitude (r=.383, P<.05) and median motor amplitude (r=.361, P<.05)., Conclusions: Contrary to our hypothesis, subjects using a greater ROM showed better nerve function than subjects propelling with a smaller ROM. Subjects using a larger ROM used less force and fewer strokes to propel their wheelchairs at a given speed. It is possible that long, smooth strokes may benefit nerve health in manual wheelchair users.

The INDEPENDENCE 3000 IBOT Transporter (IBOT) is an electronically stabilizing device for people with disabilities. The purpose of this study was to collect qualitative data on the potential for the IBOT to improve employment satisfaction of veterans who use wheelchairs to work. This study was based upon observations by trained clinicians, and responses to a survey completed by four men with traumatic spinal cord injury, who worked in an office environment. The mean age of the subjects was 52 +/- 8.8 years. The subjects used the devices to hold eye-level discussions with colleagues, climb stairs, ascend steep ramps, and negotiate curbs. When subjects were asked to rate the ease of getting around in the IBOT compared to their personal wheelchairs, they responded with a mean of 6.7 +/- 1.8 on a 10-point visual analog scale. The response to rating the overall function of the IBOT within their working environment yielded a rating of 6.0 +/- 2.8. Half of the users felt that the IBOT would help them at work and all thought it should be made available to veterans who use wheelchairs. A larger study should be conducted to determine if the IBOT affects work performance and the ability to return to work.

There is little doubt that as technologic advances become available, people with spinal cord injuries (SCIs) are living healthier, more productive, and longer lives. Federally and privately funded research, foreign competition, and globalization appear to be factors that will drive bioengineering advances within the assistive technology (AT) industry. The seeds of bioengineering research are likely to contribute to improvements in universal design and the mainstreaming of products. The aims of AT have changed tremendously in the past 50 years. Most of the federal agencies supporting assistive and rehabilitative technology research and development did not exist 50 years ago. Indeed, the leading AT companies all were established within the past 50 years. Bioengineering has the potential to be to the 21 st century what electronic engineering was to the 20th century. Advances in power electronics, telecommunications, controls, sensors, and instrumentation have really only just begun to be applied for devices to assist people with SCI. Advancing technology for people with SCI represents a significant career and business opportunity for engineers who want to serve the public good in a meaningful and tangible way.

Background: It is well established that physical activity is beneficial to health. For the individual in a wheelchair, a regular exercise program might not be available or may be too difficult to participate in physically and/or psychologically. Many exercise devices and regimes are boring. The goal, therefore, is to develop a device that makes exercise more exciting and, thus, motivates a person to exercise more or for a longer period of time, yielding increased energy expenditure. Our laboratory developed an interface between an arm ergometer and a computer game that allows the user to control game play on the screen as if using a joystick. The purpose of this study was to determine (a) whether the GAME(Cycle) system would elicit an exercise effect similar to arm ergometry, (b) whether perceived exertion would be different between the 2 devices, and (c) individuals' impressions regarding the GAME(Cycle) system., Methods: Thirteen individuals who used wheelchairs participated in the study. Participants were asked to exercise for 2 separate, 19-minute sessions. For 1 session, a GAME(Cycle) system was used and for the other session, the same arm ergometer was used, but without the computer game being played. Physiologic data and perceived exertion were collected for each session., Results: There were significant differences between playing the game and not playing the game for VO2 (P = 0.03) and VCO2 (P = 0.02), with higher values being found when the game was played. Perceived exertion was not significantly different between the 2 trials., Conclusion: GAME(Cycle) appears to be similar in nature with respect to energy expenditure to arm ergometry. Because this study was conducted on athletes, further research is needed with sedentary individuals to determine exercise effects and perceived exertion.

Objective: To investigate the relationship between pushrim forces and the progression of shoulder injuries in manual wheelchair users., Design: Longitudinal case series., Setting: Biomechanics laboratory and magnetic resonance imaging (MRI) facility at a Veterans Health Administration medical center and university hospital, respectively., Participants: Fourteen individuals with spinal cord injury (8 men, 6 women) who used manual wheelchairs., Intervention: Subjects propelled their own wheelchairs on a dynamometer at 0.9 and 1.8m/s. Bilateral biomechanical data were obtained by using force and moment sensing pushrims at time 1. Bilateral shoulder MR images were also completed on 2 occasions, at time 1 and, approximately 2 years later, at time 2., Main Outcome Measures: The peak pushrim forces in a pushrim coordinate system were calculated, weight normalized and averaged over 5 strokes (presented as % body weight). MRI abnormalities were graded by using a summated scale. Differences between scores between times 1 and 2 were calculated., Results: Subjects were divided into 2 groups based on change in MRI score. Seven subjects were in the group with worsening scores (MRI+; mean, 8.14 points; range, 5-16), and 7 were in the group with improving or unchanging scores (MRI-; mean, -1.00 point; range, -5 to 1). There was no significant difference between groups with respect to age, body mass index, or years from injury. There were significantly more women in the MRI+ group (6 women, 1 man) than in the MRI- group (7 men) (P=.001). The MRI+ group used significantly greater weight-normalized radial force, or force directed toward the axle at time 1, to propel their wheelchairs at each speed (P<.01): MRI+ at 0.9m/s (mean radial force +/- standard deviation, 5.2%+/-1.0%) and MRI- at 0.9m/s (mean radial force, 3.2%+/-1.7%) (P=.028); and MRI+ at 1.8m/s (mean radial force, 6.6%+/-1.2%) (P=.023) and MRI- at 1.8m/s (mean radial force, 4.1%+/-2.2%). In a separate analysis, women were found to propel with a significantly higher radial force. A logistic regression found a significant relationship between radial force at time 1 and increased risk of progression of MRI findings over time., Conclusion: Individuals who propel with a greater percentage of force directed toward the axle were at increased risk of progression of MRI findings over time. Most people in this group were women. Clinicians should instruct wheelchair users in effective propulsion techniques and should pay particular attention to women who use wheelchairs. Reducing forces during wheelchair propulsion may minimize the likelihood of developing shoulder injuries.

Background/objective: The objective of this study was to examine the use and efficacy of a pushrim-activated power-assist wheelchair (PAPAW) in the reduction of upper extremity range of motion (ROM) and stroke frequency in manual wheelchair users., Methods: Ten manual wheelchair users were evaluated using a repeated-measures design with and without the use of a PAPAW for maximum ROM of shoulder flexion/extension, abduction/adduction, internal/external rotation, and horizontal flexion/extension; elbow flexion/extension; wrist flexion/extension, supination/pronation, and ulnar/radial deviation; and stroke frequency. Participants propelled a Quickie 2 manual wheelchair configured as a PAPAW and their own wheelchair on a computer-controlled dynamometer at 3 different resistance levels and 2 different speeds., Results: The use of the PAPAW significantly (P < 0.05) decreased shoulder flexion/extension and horizontal flexion/extension, elbow flexion/extension, and wrist flexion/extension and ulnar/radial deviation for many speed and resistance combinations. Univariate analysis revealed that stroke frequency was unaltered in all cases., Conclusion: These findings provide the foundation for studying the utility of the PAPAW in reducing the risk of upper limb injury and neuropathy in the manual wheelchair user population.

Background: The INDEPENDENCE 3000 IBOT Transporter (IBOT) is an electronically stabilizing mobility device for people with disabilities. It operates in 4 functions: Standard, Balance (raised on 2 rear wheels), 4 Wheel (for inclines, curbs, and uneven terrain), and Remote (for loading into a vehicle)., Objective: The purpose of this study was to observe the IBOT at use in the home and in the community., Methods: Data were obtained via observations by trained clinicians, data recorded from a computerized data logger, and reports from each expert., Participants: Participants included 10 unimpaired nonwheelchair users (6 men, 4 women) and 4 expert wheelchair users (men with spinal cord injuries, T7-L1). The participants used the IBOT to perform a variety of activities, including holding eye-level discussions with colleagues and shopping by balancing on 2 wheels, going up and down steep ramps, traversing outdoor surfaces (eg, grass, dirt trails), and climbing curbs., Observations: The Balance and 4-Wheel functions were helpful and worked well. The IBOT required attention to control in the Standard function. The seat height was too high for most tables and desks, and the IBOT was challenging to use in the bathroom., Conclusion: The IBOT is a functional mobility device that expands the options of wheelchair users. It is most useful outdoors and where there is sufficient space to use its unique Balance function.

The primary objective of this study was to examine the kinematics and kinetics of the shoulder during wheelchair propulsion at a slow and moderate speed. Twenty-seven individuals with paraplegia propelled their wheelchairs at speeds of 0.9 m/s and 1.8 m/s while a motion analysis system captured movements of their upper limbs and SMART(Wheel)s simultaneously recorded their pushrim kinetics. Intraclass R correlation and Cronbach's coefficient alpha statistics revealed that all shoulder parameters were stable and consistent between strokes and speeds. The shoulder exhibited a greater range of motion, and forces and moments at the shoulder were 1.2 to 2.0 times greater (p < 0.05) during the 1.8 m/s speed trial. Peak posterior forces occurred near the end of the propulsion phase, and at the same time, the shoulder was maximally flexed and minimally abducted (p > 0.1). Shoulder positioning and the associated peak shoulder loads during propulsion may be important indicators for identifying manual wheelchair users at risk for developing shoulder pain and injury.

For individuals with a spinal cord injury or dysfunction (SCI/D), opportunities to exercise are limited and are usually not highly motivating experiences. Exercise programs or extracurricular activities may help increase or maintain the cardiovascular fitness level of individuals with SCI/D. The GAME(Wheels) system, an interface between a portable roller system and a computer, enables an individual to control a video game by propelling his or her wheelchair. The purpose of this study was to investigate whether the propulsive forces used during video play, both with and without the GAME(Wheels) system, were different. A secondary purpose was to examine differences in metabolic parameters during exercise under these two conditions. Ten manual wheelchair users exercised on the GAME(Wheels) system with and without controlling a video game. Physiological and kinetic data were collected six times during two exercise trials. Kinetic data were recorded with the SMART(Wheel) and used to investigate propulsion forces. No significant differences were found in the resultant force, rate of rise, or number of hand contacts with the pushrims. This study showed that propulsion pattern did not change significantly when wheelchair users exercised while playing a computer video game. Oxygen consumption, ventilation, and heart rate were significantly different (p < 0.05) between the two groups during the last three exercise intervals and cooldown. Playing a video game while exercising may help to motivate manual wheelchair users to exercise longer and regularly, something that was reported by this study's subjects; likewise, exercising while playing a video game may not be associated with higher pushrim forces and stroke frequencies.

Objective: This study investigated the blood lactate accumulation during two wheelchair-racing protocols. During exercise, energy is required, which causes metabolism to increase and blood lactate to accumulate. Proper training can reduce the amount of blood lactate accumulation and increase tolerance to blood lactate accumulation during aerobic exercise., Methods: Eleven male wheelchair elite track athletes with a spinal cord injury were tested to determine their blood lactate response to speed and resistance workouts. A computer-monitored wheelchair dynamometer was used during all exercise tests. The order of the test (e.g., speed or resistance workout) was randomized. Blood pressure and blood samples were taken immediately before and after completion of each exercise test., Results: The difference between the blood lactate concentrations before and after testing were 8.56 +/- 4.42, and 11.67 +/- 4.69 mM for the resistance and speed tests, respectively., Conclusions: Our results showed that the blood lactate responses were significantly different for the resistance and speed workouts.

Objective: The biomechanics of wheelchair propulsion have been linked to upper extremity injury. Specifically, prior studies have correlated increased median nerve dysfunction with increasing propulsion frequency and a higher rate of rise of the resultant, or total, pushrim force. Despite this link, there is little research on the effect of wheelchair setup on propulsion biomechanics. The objective of this study was to determine the effect of rear axle position relative to the shoulder on pushrim biomechanics., Design: Case series., Setting: Biomechanics laboratory., Participants: Forty individuals with paraplegia who use manual wheelchairs for mobility., Intervention: Subjects propelled their own wheelchairs on a dynamometer at two different steady-state speeds and going from a dead stop to maximum speed. Bilateral biomechanical data were obtained using a force- and moment-sensing pushrim and a motion analysis system., Main Outcome Measures: Position of the axle relative to the shoulder at rest both horizontal (XPOS) and vertical (YPOS), and pushrim biomechanical variables including frequency of propulsion, peak and rate of rise of the resultant force, planar moment, and push angle. Partial correlation coefficients between relative axle position and propulsion biomechanics variables were calculated., Results: After controlling for subject characteristics, XPOS was significantly correlated with the frequency of propulsion (p < .01) and the rate of rise of the resultant force (p < .05). In addition, both XPOS and YPOS were significantly correlated with the push angle at multiple speeds (p < .05)., Conclusion: Specific biomechanical parameters known to correlate with median nerve injuries were found to be related to axle position relative to the shoulder. Providing wheelchair users with adjustable axle position and then fitting the user to the wheelchair can improve propulsion biomechanics and likely reduce the risk of injury.

The sedentary lifestyle of many people with spinal cord injury (SCI) has lead to cardiovascular diseases being a major health concern. A suitable exercise program may help improve the SCI individual's cardiovascular fitness level. GAMEWheels is an interface between a custom wheelchair roller system and a computer that enables an individual to control computer video games by driving his or her wheelchair. The purpose of Phase 1 was to evaluate the design of the GAMEWheels system and to determine the type of computer video game that is likely to motivate wheelchair users to exercise. Phase 2 included physiologic testing of wheelchair users and the GAMEWheels system to investigate whether the system elicits an exercise training response. Thirty-five subjects were recruited to evaluate the GAMEWheels by playing three commercial computer games (Phase 1) and to identify the computer game that they would prefer to use when exercising. The feedback from Phase 1 was used with test subjects to verify that the GAMEWheels system elicits an exercise training effect (Phase 2). Phase 2 included 10 subjects using the GAMEWheels system to play Need for Speed II. During game play, physiologic data were collected and the subjects' oxygen consumption and heart rate were analyzed. Analysis showed that the GAMEWheels system induced nine subjects to reach their training zone, defined as 50% and 60% of their maximum oxygen consumption and heart rate, respectively. This study demonstrates that the GAMEWheels system elicits an exercise training response.

An international track wheelchair (ITWC) with a center of gravity directional controller (COGDC) is described in this paper. The rules for international track competition disallow devices designed solely for steering. Equipment has been disqualified for having steering handles, crown compensators, and other lever systems. However, the rules do allow tie-rod linkage and the use of springs for dampening caster flutter. The chair described in this paper exploits the physical properties of wheeled vehicles to achieve directional control on the track. This controller is effective, because turning is only required in one direction. Three such track wheelchairs have been developed and were used at the Paralympics in Seoul, Korea, in October of 1988.