Wheelchair Ramp Navigation in Snow and Ice-Grit Conditions

Lemaire ED, O'Neill PA, Desrosiers MM, Robertson DG. Wheelchair ramp navigation in snow and ice-grit conditions.

Objective

To explore manual wheelchair propulsion strategies for ramp ascent and descent in snow and snow-ice-grit conditions.

Design

Cross-sectional study.

Setting

Climatic Engineering and Testing Chamber (Ottawa, Canada).

Participants

Manual wheelchair users (N=11) who typically self-propel their wheelchair in winter.

Interventions

Ramp ascent and descent at 3 grades (1:10, 1:12, 1:16) and 2 winter conditions (packed snow, packed snow with a freezing rain cover, and traction grit).

Main Outcomes Measures

Type of ascent and descent strategy, success rate, number and severity of obstructions, average speed, and perceived ramp navigation rating. A questionnaire regarding the subject's past experiences with wheelchair propulsion in winter.

Results

Snow accumulation on ramps at 1:10 grade will render the ramp inaccessible for many wheelchair users who do not have external assistance. For snow conditions, the transition area from the level group to the first 2m of ramp incline were the most difficult to traverse for both ascent and descent. All subjects were able to ascend and descend the ramp for the ice-grit condition. Two-railing propulsion is a preferred strategy for ice-grit ramp navigation because of enhanced trajectory control and reducing the potential for wheel-slip problems. Backwards ramp ascent was a successful strategy for ascent in soft-snow conditions.

Conclusions

The 1:16 grade is preferred for winter ramp navigation. Backwards ramp ascent for snow conditions should be considered for people with sufficient shoulder and trunk range of motion. Two handrails are recommended for exterior ramps for both propulsion and wheelchair extraction from ruts and other snow-related obstacles. For ice ramp navigation, the amount of grit required and the effective time (ie, time to when grit becomes embedded in snow-ice, becoming much less effective) should be addressed in further research. Front wheels typically available with manual wheelchairs are not appropriate for soft-snow conditions.     

Use of a geared wheelchair wheel to reduce propulsive muscular demand during ramp ascent: Analysis of muscle activation and kinematics

Background

Shoulder muscle overuse has been linked to the high prevalence of shoulder injuries in manual wheelchair users. Ramp ascent is a barrier that is often faced by manual wheelchair users that requires higher muscle activations than level wheelchair propulsion. Additionally, reported subjective measures of shoulder pain are reduced amongst manual wheelchair users when using a wheelchair wheel outfitted with a gear mechanism. The purpose of the current investigation was to investigate shoulder muscle activation levels and upper limb kinematics during ramp ascent with and without the use of a geared wheel.

Methods

Thirteen healthy participants (6 male and 7 female) performed ramp ascent on four ramp grades (1:12, 1:10, 1:8, 1:6) using three wheel conditions (gear, no gear, standard). Electromyographic (EMG) activity of select shoulder muscles as well as kinematics of the right upper limb were collected during ramp ascent. Peak and integrated EMG as well as peak wrist, elbow, and shoulder kinematics were obtained from all ramp ascent trials.

Findings

Peak EMG of the shoulder flexors decreased by an average of 17% (P ? 0.0229) during ramp ascent with the geared wheel. Integrated EMG increased by 67% (P ? 0.0034) as a consequence of an 86% increase (P = 0.0009) in ramp ascent duration during the geared wheel condition. There were no significant differences between the non-geared and standard wheel conditions.

Interpretation

Caution must be used if using the gear ratio for prolonged periods due to potential for muscle fatigue since the overall muscle effort to move a fixed distance is higher with the gear ratio. Reducing peak demands may benefit wheelchair users with performing more strenuous tasks of daily living.     

Kinematic and Electromyographic Analysis of Wheelchair Propulsion on Ramps of Different Slopes for Young Men With Paraplegia

Chow JW, Millikan TA, Carlton LG, Chae W, Lim Y, Morse MI. Kinematic and electromyographic analysis of wheelchair propulsion on ramps of different slopes for young men with paraplegia.

Objective

To gain insight into the biomechanics of upslope wheelchair stroking by examining the changes in kinematic and electromyographic characteristics of wheelchair propulsion over ramps of different slopes.

Design

Repeated-measures design. Each subject pushed up a wooden ramp (7.3m long) 3 times at self-selected normal and fast speeds for each of these slopes: 0°, 2°, 4°, 6°, 8°, 10°, and 12°.

Setting

A biomechanics laboratory.

Participants

Young men (N=10) with paraplegia.

Interventions

Not applicable.

Main Outcome Measures

Electromyographic activity of extensor carpi radialis, triceps brachii, antero-middle and postero-middle deltoids, pectoralis major, and latissimus dorsi, and stroking kinematics.

Results

Forward lean of the trunk increased as the slope increased. The triceps brachii, antero-middle deltoid, and pectoralis major were more active during the push phase, while the postero-middle deltoid was more active during the recovery phase. Both extensor carpi radialis and latissimus dorsi were active throughout a stroke. Major adjustments in stroking kinematics and significant increases in muscle activity occurred at slopes between 4° and 10°.

Conclusion

In addition to a decrease in stroking speed, the stroking pattern becomes more compact (decreased push angle and relative recovery time, increased stroke frequency) and the trunk becomes more active with increasing slope.     

Impact of Surface Type, Wheelchair Weight, and Axle Position on Wheelchair Propulsion by Novice Older Adults

Cowan RE, Nash MS, Collinger JL, Koontz AM, Boninger ML. Impact of surface type, wheelchair weight, and axle position on wheelchair propulsion by novice older adults.

Objective

To examine the impact of surface type, wheelchair weight, and rear axle position on older adult propulsion biomechanics.

Design

Crossover trial.

Setting

Biomechanics laboratory.

Participants

Convenience sample of 53 ambulatory older adults with minimal wheelchair experience (65-87y); men, n=20; women, n=33.

Intervention

Participants propelled 4 different wheelchair configurations over 4 surfaces: tile, low carpet, high carpet, and an 8% grade ramp (surface, chair order randomized). Chair configurations included (1) unweighted chair with an anterior axle position, (2) 9.05kg weighted chair with an anterior axle position, (3) unweighted chair with a posterior axle position (Δ0.08m), and (4) 9.05kg weighted chair with a posterior axle position (Δ0.08m). Weight was added to a titanium folding chair, simulating the weight difference between very light and depot wheelchairs. Instrumented wheels measured propulsion kinetics.

Main Outcome Measures

Average self-selected velocity, push frequency, stroke length, peak resultant and tangential force.

Results

Velocity decreased as surface rolling resistance or chair weight increased. Peak resultant and tangential forces increased as chair weight increased, as surface resistance increased, and with a posterior axle position. The effect of a posterior axle position was greater on high carpet and the ramp. The effect of weight was constant, but was more easily observed on high carpet and ramp. The effects of axle position and weight were independent of one another.

Conclusion

Increased surface resistance decreases self-selected velocity and increases peak forces. Increased weight decreases self-selected velocity and increases forces. Anterior axle positions decrease forces, more so on high carpet. The effects of weight and axle position are independent. The greatest reductions in peak forces occur in lighter chairs with anterior axle positions.     

Comparison of Shoulder Muscle Electromyographic Activity During Standard Manual Wheelchair and Push-Rim Activated Power Assisted Wheelchair Propulsion in Persons With Complete Tetraplegia

Lighthall-Haubert L, Requejo PS, Mulroy SJ, Newsam CJ, Bontrager E, Gronley JK, Perry J. Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and push-rim activated power assisted wheelchair propulsion in persons with complete tetraplegia.

Objectives

To compare spatio-temporal propulsion characteristics and shoulder muscle electromyographic activity in persons with cervical spinal cord injury propelling a standard pushrim wheelchair (WC) and a commercially available pushrim-activated power assisted wheelchair (PAPAW) design on a stationary ergometer.

Design

Repeated measures.

Setting

Motion analysis laboratory within a rehabilitation hospital.

Participants

Men (N=14) with complete (American Spinal Injury Association grade A or B) tetraplegia (C6=5; C7=9).

Intervention

Participants propelled a standard pushrim WC and PAPAW during 3 propulsion conditions: self-selected free and fast and simulated 4% or 8% graded resistance propulsion.

Main Outcome Measures

Median speed, cycle length, cadence, median and peak electromyographic activity intensity, and duration of electromyographic activity in pectoralis major, anterior deltoid, supraspinatus, and infraspinatus muscles were compared between standard pushrim WC and PAPAW propulsion.

Results

A significant (P<.05) decrease in electromyographic activity intensity and duration of pectoralis major, anterior deltoid, and infraspinatus muscles and significantly reduced intensity and push phase duration of supraspinatus electromyographic activity at faster speeds and with increased resistance were seen during PAPAW propulsion.

Conclusions

For participants with complete tetraplegia, push phase shoulder muscle activity was decreased in the PAPAW compared with standard pushrim WC, indicating a reduction in demands when propelling a PAPAW.     

Preliminary outcomes of the SmartWheel Users' Group database: a proposed framework for clinicians to objectively evaluate manual wheelchair propulsion

Cowan RE, Boninger ML, Sawatzky BJ, Mazoyer BD, Cooper RA. Preliminary outcomes of the SmartWheel Users’ Group database: a proposed framework for clinicians to objectively evaluate manual wheelchair propulsion.

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.     

Comparing performance of manual wheelchair skills using new and conventional rear anti-tip devices: randomized controlled trial

Kirby RL, Corkum CG, Smith C, Rushton P, MacLeod DA, Webber A. Comparing performance of manual wheelchair skills using new and conventional rear anti-tip devices: randomized controlled trial.

Objective

To test the hypotheses that, compared with participants using manual wheelchairs equipped with conventional rear anti-tip devices (C-RADs), those using a new RAD design that deploys through an arc (Arc-RAD) perform RAD-relevant wheelchair skills better and as safely.

Design

A randomized controlled study.

Setting

A rehabilitation center.

Participants

Participants (N=30) including 16 able-bodied and 14 wheelchair users.

Intervention

Participants were provided with wheelchair skills training (up to 2.4h).

Main Outcome Measures

Total percentage score on a set of 23 RAD-relevant skills of the Wheelchair Skills Test (WST, version 3.2) administered a minimum of 3 days after training.

Results

For the C-RAD and Arc-RAD groups, the mean ± standard deviation RAD-relevant WST scores were 32.3%±8.5% and 85.1%±18.9% (Kruskal-Wallis, P<.001). Of the 23 RAD-relevant individual skills, the success rates for the Arc-RAD group were at least 20% higher (the criterion we set for clinical significance) in 17 (74%). For the C-RAD group, the success rate was 0% for the 12 wheelie-dependent skills, the 13-cm-high obstacle, and the 15-cm level change ascent. There were no serious adverse effects in either group.

Conclusions

The new RAD design allows much better performance on relevant wheelchair skills than the conventional design without compromising safety.     

Demographic and Clinical Variation in Veterans Health Administration Provision of Assistive Technology Devices to Veterans Poststroke

Hubbard Winkler SL, Cowper Ripley DC, Wu S, Reker DM, Vogel B, Fitzgerald SG, Mann WC, Hoenig H. Demographic and clinical variation in Veterans Health Administration provision of assistive technology devices to veterans poststroke.

Objectives

To examine variation in provision of assistive technology (AT) devices and the extent to which such variation may be explained by patient characteristics or Veterans Health Administration (VHA) administrative region.

Design

Retrospective population-based study.

Setting

VHA.

Participants

Veterans poststroke in fiscal years 2001 and 2002 (N=12,046).

Interventions

Not applicable.

Main Outcome Measure

Provision of 8 categories of AT devices.

Results

There was considerable regional variation in provision of AT. For example, differences across administrative regions in the VHA ranged from 5.1 to 28.1 standard manual wheelchairs per 100 veterans poststroke. Using logistic regression, with only demographic variables as predictors of standard manual wheelchair provision, the c statistic was .62, and the pseudo R² was 2.5%. Adding disease severity increased the c statistic to .67 and the pseudo R² to 6.2%, and adding Veteran Integrated Network System further increased the c statistic to .72 and pseudo R² to 9.8%.

Conclusions

Our research showed significant variation in the provision of AT devices to veterans poststroke, and it showed that patient characteristics accounted for only 6.2% of the variation. VHA administrative region and disability severity accounted for equivalent amounts of the variation. Our findings suggest the need for improvements in the process for providing AT and/or provider education concerning device provision.     

Environmental barriers to and availability of healthy foods for people with mobility disabilities living in urban and suburban neighborhoods

Mojtahedi MC, Boblick P, Rimmer JH, Rowland JL, Jones RA, Braunschweig CL. Environmental barriers to and availability of healthy foods for people with mobility disabilities living in urban and suburban neighborhoods.

Objective

To assess the impact of the built environment on access to healthy foods for people with mobility disabilities by measuring wheelchair accessibility of grocery stores and availability of healthy affordable foods.

Design

A survey consisting of 87 questions.

Setting

A low-income, multiracial urban Chicago neighborhood with a 3-mile radius was compared with a suburban neighborhood of the same size in which the population is similar in income level and racial distribution.

Participants

Not applicable.

Interventions

Not applicable.

Main Outcome Measures

Accessibility issues outside and within grocery stores and the availability of healthy affordable food items in these grocery stores.

Results

The urban area had more stores (n=48) than the suburban area (n=34); however, only 46% of urban stores had an entrance that would allow an individual requiring a ramp or level entrance to gain access compared with 88% of suburban stores (P<.001). Wheelchair accessibility characteristics of grocery and convenience stores did not differ between the urban and suburban areas. The availability of healthy affordable foods in urban and suburban stores was relatively low, with only 33% to 40% of the 18 items available, and did not differ between urban and suburban stores.

Conclusions

People with mobility impairments are at a disadvantage in maintaining healthy food choices because of limited access to stores and healthy foods.     

Longitudinal Changes in Physical Capacity Over 20 Years in Athletes With Spinal Cord Injury

Shiba S, Okawa H, Uenishi H, Koike Y, Yamauchi K, Asayama K, Nakamura T, Tajima F. Longitudinal changes in physical capacity over 20 years in athletes with spinal cord injury.

Objective

To investigate the longitudinal changes in physical capacity over 20 years in athletes with spinal cord injury (SCI).

Design

Longitudinal study (20-y follow-up).

Setting

Laboratory setting.

Participants

Persons with SCI (N=7).

Interventions

Not applicable.

Main Outcome Measures

Maximum oxygen consumption V?o₂max) measured in 1986-1988 and in 2006.

Results

Subjects with SCI maintained stable V?o₂max in 2006. Six of the 7 continued various wheelchair sports activities, while 1 person quit sports activities 1 year after the baseline study. The latter person showed reduced V?o₂max by 53%, while 2 persons who continued strenuous wheelchair sports activities showed increased V?o₂max by 43% and 45% after 20 years.

Conclusion

The results indicated that physical capacity reflected the level of sports activity in subjects with SCI who maintained sports activities.     

The Effects of Foot Position on the Performance of the Sit-To-Stand Movement With Chronic Stroke Subjects

Camargos AC, Rodrigues-de-Paula-Goulart F, Teixeira-Salmela LF. The effects of foot position on the performance of the sit-to-stand movement with chronic stroke subjects.

Objective

To investigate the effects of different foot positions during the sit-to-stand (STS) movements with stroke subjects.

Design

Cross-sectional.

Setting

Research laboratory.

Participants

Twelve chronic stroke subjects (N=12).

Interventions

Not applicable.

Main Outcome Measures

Differential latency and electromyography (EMG) activity of the tibialis anterior, soleus, quadriceps, and hamstring muscles of the affected leg as well as the movement time, time of seat-off, weight symmetry, and rising index were obtained while the subjects performed the STS movements by using 4 different strategies: spontaneous; symmetric; asymmetric-1, with the affected foot behind; and asymmetric-2, with the unaffected foot behind.

Results

Compared with the spontaneous strategy, the soleus showed the greatest differential latency in the asymmetric-2 strategy, the hamstrings had lower EMG activity in the symmetric strategy, and the movement time was greater in the asymmetric strategies.

Conclusions

The asymmetric 2 strategy appeared to be the least favorable, whereas the spontaneous and the symmetric strategies appeared to be more favorable in improving the STS performance. Based on these findings, allowing the subjects to adopt the spontaneous strategy or training of the symmetric strategy could result in greater benefits for subjects with higher chronicity and higher functional levels, such as those evaluated in the present study.     

Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders

Boe SG, Rice CL, Doherty TJ. Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders.

Objectives

To assess the utility of the surface electromyographic signal as a means of estimating the level of muscle force during quantitative electromyography studies by examining the relationship between muscle force and the amplitude of the surface electromyographic activity signal; and to determine the impact of a reduction in the number of motor units on this relationship, through inclusion of a sample of patients with neuromuscular disease.

Design

Cross-sectional, cohort study design.

Setting

Tertiary care, ambulatory, electromyography laboratory.

Participants

A volunteer, convenience sample of healthy control subjects (n=10), patients with amyotrophic lateral sclerosis (n=9), and patients with Charcot-Marie-Tooth disease type X (n=5).

Interventions

Not applicable.

Main Outcome Measures

The first dorsal interosseous (FDI) and biceps brachii muscles were examined. Force values (at 10% increments) were calculated from two 4-second maximal voluntary contractions (MVCs). Surface electromyographic activity was recorded during separate 4-second voluntary contractions at 9 force increments (10% -90% of MVC). Additionally, a motor unit number estimate was derived for each subject to quantify the degree of motor unit loss in patients relative to control subjects.

Results

The relationships between force and surface electromyographic activity for both muscles (controls and patients) were best fit by a linear function. The variability about the grouped regression lines was quantified by 95% confidence intervals and found to be ±6.7% (controls) and ±8.5% (patients) for the FDI and ±5% (controls) and ±6.1% (patients) for the biceps brachii.

Conclusions

These results suggest that the amplitude of the surface electromyographic activity signal may be used as a means of estimating the level of muscle force during quantitative electromyography studies. Future studies should be directed at examining if the variability associated with these force and surface electromyographic activity relationships is acceptable in replacing previous methods of measuring muscle force.     

Ability of People With Stroke to Learn Powered Wheelchair Skills: A Pilot Study

Mountain AD, Kirby RL, Eskes GA, Smith C, Duncan H, MacLeod DA, Thompson K. Ability of people with stroke to learn powered wheelchair skills: a pilot study.

Objectives

Our primary objective was to test the hypothesis that people with stroke can learn to use powered wheelchairs safely and effectively. Our secondary objective was to explore the influence of visuospatial neglect on the ability to learn powered wheelchair skills.

Design

Prospective, uncontrolled pilot study using within-participant comparisons.

Setting

Rehabilitation center.

Participants

Inpatients (N=10; 6 with visuospatial neglect), all with a primary diagnosis of stroke.

Interventions

Participants received 5 wheelchair skills training sessions of up to 30 minutes each using the Wheelchair Skills Training Program (version 3.2).

Main Outcome Measures

Powered wheelchair skills were tested before and after training using the Wheelchair Skills Test, Power Mobility version 3.2 (WST-P).

Results

The group's total mean WST-P scores improved from 25.5% of skills passed at baseline to 71.5% posttraining (P=.002). The participants with neglect improved their WST-P scores to the same extent as the participants without neglect, although their pretraining and posttraining scores were lower. The training and testing sessions were well tolerated by the participants, and there were no serious adverse events.

Conclusions

Many people with stroke, with or without visuospatial neglect, can learn to use powered wheelchairs safely and effectively with appropriate training.     

Rates and Predictors of Manual and Powered Wheelchair Use for Persons With Stroke: A Retrospective Study in a Canadian Rehabilitation Center

Mountain AD, Kirby RL, MacLeod DA, Thompson K. Rates and predictors of manual and powered wheelchair use for persons with stroke: a retrospective study in a Canadian rehabilitation center.

Objectives

To determine the rates of manual and powered wheelchair use at discharge for people with stroke admitted to a rehabilitation center and to determine whether any predictors of wheelchair use at discharge could be identified.

Design

Retrospective cohort study.

Setting

Rehabilitation center.

Participants

Consecutive former inpatients (N=100) with a primary diagnosis of stroke, a sample of convenience.

Interventions

None.

Main Outcome Measures

We reviewed the inpatient health records to determine the rates of wheelchair use at discharge and to record some readily available demographic and clinical data that might serve as predictors of wheelchair use.

Results

At discharge, 40 people (40%) were using manual wheelchairs, 1 person (1%) was using a powered wheelchair, and 59 (59%) were not using a wheelchair. Of the patients who were walkers on admission (ie, walking FIM scores of 6 or 7), none (0%) used wheelchairs at discharge. Of those with nonwalking FIM scores (1-5) on admission, 56% were using wheelchairs at discharge. Multivariate analyses revealed that the adjusted odds ratios of using a wheelchair (manual or powered) were 3.33 (95% confidence interval [CI], 1.33-8.33) for those with left-hemisphere versus right-hemisphere strokes (P=.010), .94 (CI, .91-.96) for each point rise in the total raw FIM score on admission (P<.0001), and 19.46 (CI, 6.33-59.81) if the total admission FIM score was less than 80 versus greater than or equal to 80 (P<.0001).

Conclusions

On discharge from our rehabilitation center, 40% of people with stroke were using manual wheelchairs and 1% powered wheelchairs. People who were not walking on admission, those with left-hemisphere strokes, and those with lower total admission FIM scores were more likely to use a wheelchair. These findings may permit clinicians to predict wheelchair use better early in the rehabilitation process, when it can affect rehabilitation planning.     

Generalization of Prism Adaptation for Wheelchair Driving Task in Patients With Unilateral Spatial Neglect

Watanabe S, Amimoto K. Generalization of prism adaptation for wheelchair driving task in patients with unilateral spatial neglect.

Objectives

To verify the efficacy of prism adaptation as a practical means of rehabilitation for subjects with unilateral spatial neglect by conducting goal-directed tasks in the presence of similar visual flankers in the right hemispace using an activity of daily living, namely, wheelchair operation.

Design

Prospective cohort study.

Setting

Rehabilitation center located in Japan.

Participants

Patients with unilateral spatial neglect (N=10).

Intervention

Prism adaptation.

Main Outcome Measures

A midpoint-directed task in which the subject faces the center of 2 symbols placed in front and moves the wheelchair toward it, and a goal-directed task in which the subject must differentiate a single target from multiple symbols and move the wheelchair toward it.

Results

In the midpoint-directed task, there was a significant shift in the reach position bias from +27.7cm prior to prism adaptation to +3.1cm after prism adaptation (P<.01). In the goal-directed task, the time taken to reach the outer left target decreased from 21.2 seconds prior to prism adaptation to 11.8 seconds after prism adaptation, and the difference between placement of the targets was eliminated.

Conclusions

Prism adaptation exhibited the potential to generalize the effects on activities of daily living such as driving a wheelchair and to ameliorate unilateral spatial neglect even in the presence of right-hemispace flankers. Prism adaptation is an effective therapeutic modality in rehabilitation because it prevents the appearance of neglect symptoms despite situational or contextual changes.     

Wheelchair-Related Falls in Veterans With Spinal Cord Injury Residing in the Community: A Prospective Cohort Study

Nelson AL, Groer S, Palacios P, Mitchell D, Sabharwal S, Kirby RL, Gavin-Dreschnack D, Powell-Cope G. Wheelchair-related falls in veterans with spinal cord injury residing in the community: a prospective cohort study.

Objectives

(1) To determine the incidence of wheelchair falls and fall-related injuries in persons with spinal cord injury (SCI) living in the community. (2) To predict wheelchair-related falls and associated injuries from specific parameters including characteristics of the wheelchair user, wheelchair type and features, health care practices, wheelchair activities, and physical environment.

Design

This prospective cohort study followed participants monthly over 1 year; data were collected through surveys, interviews, performance testing, observation, and medical records.

Setting

Three Veterans' Administration hospitals.

Participants

Convenience sample of community-dwelling persons with SCI who used a wheelchair as their primary means of mobility (N=702).

Interventions

Not applicable.

Main Outcome Measures

Self-reports of wheelchair falls and fall-related injuries, Wheelchair User Characteristics Survey, Health Status Checklist, Health-Related Behaviors, Zuckerman Sensation Seeking Scale, Wheelchair and Equipment-Related Behaviors, Wheelchair Characteristics, Wheelchair Skills Test, and Physical Environment Assessment.

Results

Of the 659 subjects who completed the study, 204 participants (31%) reported 553 fall events, and 95 subjects (14%) were injured as a result of wheelchair falls. A logistic regression model for predicting wheelchair falls identified 6 significant risk factors: pain in previous 2 months, alcohol abuse, greater motor function, history of previous fall, fewer SCI years, and shorter length of wheelchair. Eighty-two percent of the variance for wheelchair fall events was explained by these 6 variables. A logistic regression model for predicting injurious falls identified 4 significant risk factors: pain in previous 2 months, greater motor function, history of previous fall, and inaccessible home entrance. These 4 factors were able to explain 81% of the variance for injurious falls.

Conclusions

This is the first study to determine the incidence of wheelchair-related falls in community-dwelling people with SCI who use a wheelchair. Results indicate the incidence of falls was 31% and injurious falls was 14%. Those at greatest risk can be predicted from some readily available information regarding their clinical status, wheelchair features, and home environment.