Predicting psychosocial outcomes using a brief measure of quality of life in a sample of people with spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) significantly impacts an individual's quality of life (QOL). A brief and subjective measure of QOL is necessary to monitor the progress and outcomes of SCI rehabilitation. OBJECTIVE: To determine whether this measure of QOL was associated with clinically important physical and psychosocial outcomes in a sample of people with SCI, to determine how people with SCI scored on this measure of QOL, and to determine whether people with SCI scored differently than nondisabled individuals on the QOL scale. METHODS: Participants were 134 people with SCI (65% male; 35% female) and 227 nondisabled people (35% male; 65% female). Participants were assessed on a number of psychosocial and physiological variables at a large urban university and rehabilitation center. Variables examined were QOL, life satisfaction, depression, social interaction, pain, fatigue, and level of functioning. RESULTS: Participants with SCI reported more low QOL scores and fewer high QOL scores than the nondisabled group. For participants with SCI, QOL was positively related to life satisfaction and social interaction and negatively related to pain, fatigue, and depression. CONCLUSIONS: Participants with SCI scored lower on the QOL measure than those without a disability, although the difference was not clinically significant. QOL was unrelated to level of functioning; people may still experience a high QOL despite their physical limitations. Depression and social interaction were significantly related to QOL and should be secondary targets for intervention following SCI rehabilitation.

Cardiometabolic changes and disparities among persons with spinal cord injury: a 17-year cohort study.

BACKGROUND: Cardiometabolic syndrome in individuals who are aging with spinal cord injury (SCI) increases the risk of cardiovascular disease and diabetes. Longitudinal research is needed on the natural progression of cardiometabolic syndrome in SCI. OBJECTIVE: To identify the magnitude of changes in biomarkers of cardiometabolic syndrome and diabetes over time in people aging with SCI, and to discern how these biomarkers relate to demographics of race/ethnicity and sex. METHODS: This cohort study was a follow-up of a convenience sample of 150 participants (mean age, 51.3; duration of SCI, 27.3 years) from a full cohort of 845 who participated in research in which physiologic and serologic data on cardiovascular disease had been prospectively collected (1993-1997). Inclusion criteria were adults with traumatic-onset SCI. Average years to follow-up were 15.7 ± 0.9. Assessments were age, race, level and completeness of injury, duration of injury, blood pressure, body mass index, waist circumference, serum lipids, fasting glucose, hemoglobin A1c, and medications used. Primary outcome was meeting at least 3 of the criteria for cardiometabolic syndrome. RESULTS: The frequency of cardiometabolic syndrome increased significantly from 6.7% to 20.8% or 38.2% according to 2 definitions. It was significantly higher in Hispanics and apparently higher in women. Diabetes increased significantly by a factor of 6.7. CONCLUSION: Our data indicate clinically important increases in the frequency of cardiometabolic syndrome, especially among Hispanic and female participants, and a similar increase in diabetes among individuals aging with SCI. Clinical practice guidelines need to be customized for women and Hispanics with SCI.

Predictors of subclinical atherosclerosis in women with spinal cord injury.

BACKGROUND: Chronic spinal cord injury (SCI) is associated with an increase in risk factors for cardiovascular disease (CVD). In the general population, atherosclerosis in women occurs later than in men and usually presents differently. Associations between risk factors and incidence of CVD have not been studied in women with SCI. OBJECTIVE: To determine which risk factors for CVD are associated with increased carotid intima-media thickness (CIMT), a common indicator of atherosclerosis, in women with SCI. METHODS: One hundred and twenty-two females older than 18 years with traumatic SCI at least 2 years prior to entering the study were evaluated. Participants were asymptomatic and without evidence of CVD. Exclusion criteria were acute illness, overt heart disease, diabetes, and treatment with cardiac drugs, lipid-lowering medication, or antidiabetic agents. Measures for all participants were age, race, smoking status, level and completeness of injury, duration of injury, body mass index, serum lipids, fasting glucose, hemoglobin A1c, and ultrasonographic measurements of CIMT. Hierarchical multiple linear regression was conducted to predict CIMT from demographic and physiologic variables. RESULTS: Several variables were significantly correlated with CIMT during univariate analyses, including glucose, hemoglobin A1c, age, and race/ethnicity; but only age was significant in the hierarchical regression analysis. CONCLUSIONS: Our data indicate the importance of CVD in women with SCI.

Effects of reduction in shoulder pain on quality of life and community activities among people living long-term with SCI paraplegia: a randomized control trial.

OBJECTIVE/BACKGROUND: People with spinal cord injury (SCI) paraplegia can develop shoulder problems over time, which may also cause pain. Shoulder pain may complicate or interfere with a person's daily activities, social events, and their overall quality of life (QOL). The purpose of this study was to examine changes in social interaction and QOL after an exercise treatment for shoulder pain in people with SCI paraplegia. DESIGN: Fifty-eight participants with SCI paraplegia who were also experiencing shoulder pain were selected and randomized to either an exercise treatment or a control group. Participants in the treatment group participated in a 12-week, at-home, exercise and movement optimization program designed to strengthen shoulder muscles and modify movements related to upper extremity weight bearing. METHODS: Participants filled out self-report measures at baseline, 12 weeks later at the end of treatment, and at a 4-week follow-up. OUTCOME MEASURES: The Wheelchair User's Shoulder Pain Index (WUSPI), the Social Interaction Inventory (SII), and the Subjective Quality of Life Scale. RESULTS: From the baseline to the end of treatment, repeated-measures analysis of variance revealed a significant interaction between WUSPI and SII scores, P < 0.001, and between WUSPI and QOL scores, P < 0.001. CONCLUSION: Reductions in shoulder pain were related to significant increases in social participation and improvements in QOL. However, increases in social participation did not significantly affect improvements in QOL.

Disparities in subjective well-being, participation, and health after spinal cord injury: a 6-year longitudinal study.

OBJECTIVE: To identify disparities and changes in subjective well-being, participation, and health over a 6-year period as a function of race-ethnicity and gender in persons with spinal cord injury (SCI). METHODS: Stratified sampling was used to maximize inclusion of women and racial-ethnic minorities. Three model SCI systems participated, representing the Southeastern, Western, and Mountain regions of the United States. 250 participants completed measures on two occasions. Similar portions of Caucasians (n = 62), African-Americans (n = 61), American-Indians (n = 56), and Hispanics (n = 71) participated. Women made up approximately 43.1% of the sample. Three sets of outcome measures assessed: (a) subjective well-being and depressive symptoms, (b) participation, and (c) health. RESULTS: MANOVA indicated significant effects for race-ethnicity (between subjects effect) and time (within subjects effect) but not for gender or the interaction effects. A Bonferroni correction was used to compare outcomes as a function of race-ethnicity and time. Five outcomes were significantly related to race-ethnicity, whereas no items were significantly related to the time effect after the Bonferroni correction. Caucasians reported best subjective well-being scores in several domains followed by African-Americans. Caucasians also reported more hours out of bed than either African-Americans or Hispanics. CONCLUSION: Over a 6-year period, race-ethnicity continued to be related to differences in subjective well-being and participation but not health. Disparities in outcomes did not systematically increase or diminish over time, suggesting that once developed, such disparities are unlikely to change in the absence of intervention.

Effects of assistive technology on functional decline in people aging with a disability.

This study used a randomized control group design to investigate the impact of an assistive technology and home modification intervention on function for individuals who are aging with a disability. There were 91 participants with polio, rheumatoid arthritis, cerebral palsy, spinal cord injury, stroke, and other impairments. Outcome data were collected at 12 and 24 months through in-home interviews using the Older Americans Resources and Services Instrument (OARS) and the Functional Independence Measure (FIM), and through monthly telephone contact on the hours of in-home care, hospitalizations, and acquisition of AT. The treatment group received an in-home evaluation of their equipment and home modification needs. All recommended AT and home modifications were provided and paid for in full or in part by the study. The control group received the standard community-available health care. A significant "group by time" interaction for the FIM suggested a slower decline in function for the treatment group over 2 years. Further analyses found that the treatment group was more likely to use equipment to maintain independence vs. personal assistance. This study supports the value of assistive technology for adults aging with a disability and suggests that it be provided earlier in the aging process.

Five-year longitudinal bone evaluations in individuals with chronic complete spinal cord injury.

BACKGROUND/OBJECTIVES: Knowledge of spinal cord injury (SCI) bone changes has been derived primarily through cross-sectional studies, many of which are controvertible. Longitudinal studies are sparse, and long-term longitudinal chronic studies are unavailable. The objective of this study was to provide a clearer perception of chronic longitudinal bone variations in people with complete SCI. METHODS: Bone status of 31 individuals with chronic, complete SCI was assessed twice using dual-energy xray absorptiometry at an average interval of 5.06 +/- 0.9 years. Because the sample of women was small (4), the primary analyses of change and comparisons of those with paraplegia vs tetraplegia were confined to the male participants. RESULTS: Spine Z-scores showed a significant increase (P < 0.0001). The average Z-scores, initial and followup, were within the normal range. Hip Z-scores also showed a significant increase (P < 0.0001), and hip bone mineral density (BMD) increased in 48% of the participants. Knee BMD and lower extremity total bone mineral showed significant decreases (P < 0.003 and P < 0.02, respectively), but increases were seen in 33% and 26% at the respective sites. Individuals with tetraplegia had significantly lower values across all regions (P < 0.0001), and changes were significantly different compared with paraplegia (P < 0.0001). Bone values and changes in men vs women, despite the small sample of women, showed highly significant differences (P < 0.003-0.002). CONCLUSION: Chronic effects of complete SCI do not exclusively result in continued loss of BMD or a static state of lowered BMD; gain in BMD may occur. The nature and magnitude of the effects of complete SCI on BMD vary by site, with sex and level of injury, which has implications for treatment and its assessment.

Mobile arm supports: evidence-based benefits and criteria for use.

BACKGROUND/OBJECTIVE: To collect data from therapists regarding criteria for use and activities that individuals with C4-C5 tetraplegia can perform using a mobile arm support (MAS) that they otherwise could not. Reasons for nonuse, equipment design limitations, and therapist training needs were also studied. METHODS: A modified Delphi approach was used to conduct an e-mail survey for which the response to each question was analyzed and used to formulate the subsequent question. SETTING: Rehabilitation centers. PARTICIPANTS: Eighteen occupational therapists (most affiliated with 1 of the federally designated Model Spinal Cord Injury Systems) with extensive experience in the treatment of individuals with spinal cord injury (SCI). RESULTS: The key physical prerequisite for successful use of the MAS was at least minimal strength of the deltoid and biceps muscles; 92% of respondents indicated that they would fit an MAS for motivated patients having very weak (<2/5) biceps and deltoid muscles. According to the therapists, 100% (n = 30) of their clients were able to perform at least 1 activity using a MAS that they were unable to perform without the device. These activities included (in descending frequency) eating, page turning, driving a power wheelchair, brushing teeth, keyboarding, writing, name signing, drawing, painting, scratching nose, playing board games, accessing electronic devices, drinking, and grooming. Equipment design limitations included increased wheelchair width and problems managing the arms while reclining. CONCLUSIONS: Mobile arm supports allow persons with C4-C5 tetraplegia to engage in activities that they otherwise cannot perform with their arms.

Clinical significance of abnormal electrocardiographic findings in individuals aging with spinal injury and abnormal lipid profiles.

BACKGROUND: Cardiovascular risk factors are common in individuals with chronic spinal cord injury (SCI), and their prevalence increases with age. The actual prevalence of overt cardiovascular disease (CVD) in this population has not been well established. METHODS: Electrocardiograms (ECGs) were examined for abnormalities in 43 individuals with abnormal lipid profiles being followed in the outpatient SCI clinic of our institution. The mean age of the study population of predominantly men was 43 +/- 9.9 years and the mean duration of injury 16.6 +/- 8 years. RESULTS: ECG abnormalities were common and present in 60.5% of participants. ST-T wave abnormalities were the most commonly observed (35%). Evidence of previous myocardial infarction was present in 7% of all individuals and in 12% of those with ECG abnormalities. The only clinical parameter differentiating the group with normal vs abnormal ECG was the duration of injury (19.5 +/- 8 y vs 12 +/- 5 y; P = 0.0026). Analysis of variance showed that injury duration was the sole predictor of abnormal ECG with 68% accuracy (P = 0.006). Among those with ECG abnormalities, although no significant differences were detected between those with and without evidence of previous myocardial infarction, mean total cholesterol and low-density lipoprotein were higher, and mean high-density lipoprotein was lower. Mean age and injury duration were greater in those with evidence of previous myocardial infarction. CONCLUSION: Although age is an important risk factor for CVD in the population of individuals without disabilities, injury duration is at least as important as age in those with SCI. Our findings support the recommendation that individuals with SCI and abnormal lipids should be screened for CVD regardless of age.

Correlates of a Single-Item Quality-of-Life Measure in People Aging with Disabilities.

OBJECTIVE: Practical quality-of-life (QOL) screening methods are needed to help focus clinical decision-making on what matters to individuals with disabilities. DESIGN: A secondary analysis of a database from a large study of adults aging with impairments focused on four diagnostic groups: cerebral palsy (n = 134), polio (n = 321), rheumatoid arthritis (n = 99), and stroke (n = 82). Approximately 20% of cases were repeated measures of the same individuals 3-5 yrs later. Functional levels, depression, and social interactions were assessed. The single-item, subjective, seven-point Kemp Quality of Life Scale measured QOL. For each diagnostic group, Kemp Quality of Life Scale responses were divided into low, average, and high QOL subgroups. Analysis of variance and Tukey honestly significant difference tests compared clinical characteristics among these subgroups. RESULTS: Duration of disability varied among the four groups. Within each group, QOL subgroups were similar in age, sex, and duration of disability. Low mean QOL was associated with lower functional level, higher depression scores, and lower social interaction (P < 0.001) in all four groups. In contrast, high mean QOL was associated with higher social interaction (P < 0.001). CONCLUSION: The Kemp Quality of Life Scale relates significantly to clinically relevant variables in adults with impairments. The scale's utility in direct clinical care merits further examination.

Factors influencing body composition in persons with spinal cord injury: a cross-sectional study.

To determine the body composition differences across age, 133 men with chronic spinal cord injury (SCI) (66 with tetraplegia, 67 with paraplegia) were compared with an age-, height-, and ethnicity-matched able-bodied male reference population (n = 100) using two different dual-energy X-ray absorptiometry densitometers. The effects of duration of injury, level, and completeness of lesion were analyzed in the SCI population. Independent of age, total body and regional lean mass were lower and fat mass was higher in persons with SCI compared with controls. The SCI group was 13 +/- 1% (means +/- SE) fatter per unit of body mass index (kg/m2) compared with the control group (P < 0.0001). Advancing age was strongly associated with less lean mass and greater adiposity in those with SCI, whereas it was mildly related in the controls. Total body and regional arm and trunk, but not leg, lean tissues were lower in subjects with SCI, across all ages, than in the controls. In summary, persons with SCI were fatter for any body mass index and demonstrated significantly less lean and more adipose tissues for any given age compared with controls.

Research and interpretation perspectives on aging related physical morbidity with spinal cord injury and brief review of systems.

There are number of perspectives associated with the scientific study and interpretation of aging in the general population that also relate to the study of aging with spinal cord injury (SCI). These include era and survivor effects and have implications for design, analysis and interpretation of SCI aging research, which, in turn, have implications for planning, policy and clinical practice. Several factors specifically related to SCI also have implications for design, analysis and interpretation of SCI aging research. These include duration of injury, age at injury, neurological impairment (level and completeness of injury), and gender. Considering the skin, musculoskeletal, cardiovascular, respiratory, genitourinary, gastrointestinal, nervous, endocrine, and immune physiologic systems, appropriate research specific to a particular system and related morbidity in those aging with spinal cord injury is currently limited to the musculoskeletal, cardiovascular and respiratory systems. Research on certain aspects of aging with SCI is not currently feasible due to the rate and magnitude of historical changes in treatment and rehabilitation of SCI; and currently most research pertaining to aging with SCI will be highly subject to survivor effects. Nevertheless, there is a need for research on aging with SCI and many opportunities with regard to gaps in knowledge.

Risk factors for osteoporosis at the knee in the spinal cord injury population.

BACKGROUND: The objective of this study was to determine modifiable and nonmodifiable risk factors for bone loss at the knee in individuals with spinal cord injury (SCI) by examining known risk factors for osteoporosis in the general population and additional, unique nonmodifiable SCI elements including age at injury onset, injury duration, and extent of neurologic injury (level and completeness). METHODS: Risk factors were examined by logistic regression in 152 individuals with chronic SCI. Knees were classified as osteoporotic based on whether bone mineral density (BMD) of the knee as assessed by dual-energy x-ray absorptiometry fell within the 95% confidence interval of the BMD of the knee of individuals who had experienced fractures at the knee. RESULTS: Accuracy for predicted membership in the osteoporotic group and nonosteoporotic group were 79.22% and 69.33%, respectively. Of all variables included in the analysis, 3 had a significant effect on predicted group membership: completeness of injury (P < 0.0001), body mass index (BMI) (P = 0.0035), and age (P = 0.0394). Individuals with complete injuries were 6.17 times (617%) more likely to have BMD of the knee low enough to place them in the osteoporotic category. The odds ratio for BMI indicated that every unit increase in BMI lowered the odds of being in the osteoporotic group by 11.29%. The odds ratio for age indicated that every 1-year increase in age increased the odds of being in the osteoporotic group by 3.54%. No other modifiable or nonmodifiable risk factors were significant predictors. CONCLUSION: Completeness of injury dictates and overrides most modifiable and nonmodifiable risk factors for bone loss at the knee leading to pathologic fractures in SCI. SCI osteoporosis may be classified more appropriately as neurogenic in origin.

Treatment of major depression in individuals with spinal cord injury.

OBJECTIVE: This study evaluated the effects of treating major depression in individuals with spinal cord injury (SCI), focusing on the degree of improvement and correlated changes that could be expected in 6 months of treatment. DESIGN: A pretreatment-posttreatment design was used. Random assignment to a nontreatment group could not be implemented ethically. Therefore, this study compared participants who declined treatment to persons who accepted treatment over a 24-month period. SETTING AND PARTICIPANTS: Participants were outpatients of a large urban rehabilitation center in southern California. Twenty-eight participants who accepted treatment were assigned to a treatment group; 15 individuals who declined treatment were assigned to a nontreatment group. The age of the participants ranged from 20 to 74 years. Varying levels of SCI dysfunction were represented. INTERVENTIONS: A 6-month combination of psychotherapy and antidepressant medication. OUTCOME MEASURES: A depression inventory, a community activities checklist, and a life satisfaction scale. RESULTS: A significant (P < 0.001) 57% reduction in depressive symptoms occurred in the treatment group, whereas there was no significant change in the nontreatment group. At the end of 6 months, 30% of participants had no depression, 42% had minor depression, and 29% still had major depression, but to a lesser degree. Community activities increased significantly over the treatment period, as did life satisfaction. CONCLUSION: The results suggest that depression is treatable in this population, although 6 months may not be sufficient to reach maximum benefit in all cases. This study further identified obstacles that limited the ability to randomize participants into treatment arms and made it difficult to deliver services to all those in need. Complications related to SCI, such as difficulties in transportation, likely restrict the ability to implement needed services to many individuals with SCI.

Bone loss at the os calcis compared with bone loss at the knee in individuals with spinal cord injury.

BACKGROUND/OBJECTIVE: The objective of this study was to document acute bone loss at the os calcis and compare it with bone loss at the knee following spinal cord injury (SCI) as a potential proxy for bone loss in individuals with SCI. METHODS: Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DEXA) at the knee and os calcis, which also was assessed by ultrasound in 6 individuals--5 with complete SCI and 1 with incomplete SCI--at means of 33.5 and 523 days following injury. RESULTS: Bone mineral was progressively greater as measured from proximal to distal sites. The net average BMD of the knee declined 24% (P = 0.017). The distal femur lost 27% (P = 0.038) and the proximal tibia lost 32% (P = 0.015), whereas the os calcis lost 38% (P = 0.001) as measured by DEXA and 49% (P < 0.001) as estimated from ultrasound. The mean loss of 24% at the knee was significantly different from the loss percentages at the os calcis as measured by both techniques: DEXA (P = 0.036) and ultrasound (P = 0.043). Differences between annualized loss rates at the knee and the os calcis measured by both techniques also were significant: DEXA (P = 0.032) vs ultrasound (P = 0.038). However, annualized loss rates demonstrated the same trend for differential loss at the sites examined in the 5 individuals with complete injuries but not for the 1 participant with an incomplete injury. The loss rates were similar for the complete and incomplete participants at the os calcis, but not at the knee. CONCLUSION: The BMD of the os calcis declined 38% by DEXA and 49% by ultrasound compared with 24% at the knee when measured 1 to 1.5 years after injury. BMD of the os calcis and distal femur measured by DEXA in persons with complete SCI were highly correlated (r = 0.84, P < 0.0001).

Incidence and clinical correlates of increased serum creatine kinase levels in persons with spinal cord injury.

BACKGROUND: Elevated plasma levels of creatine kinase (CPK) are found in various neuromuscular conditions as a result of muscle damage and necrosis. Elevated CPK has also been described in elite wheelchair athletes and in able-bodied individuals after strenuous exercise. METHODS: The incidence of elevated CPK in individuals with spinal cord injury (SCI) has not been well established. We reviewed laboratory data from 581 individuals with chronic SCI. RESULTS: Most individuals with SCI (73.3%) had CPK values within 95% confidence intervals for able-bodied individuals. The highest levels were seen in African Americans (21% had CPK values > 95 confidence intervals for able-bodied individuals). Significant associations between CPK and the following independent variables were identified: impairment group, gender, duration of injury, body mass index, and ethnic group. Multiple regression analysis revealed significant correlations between CPK and oxygen consumption (beta .37, P < .01) in 32 individuals who performed the exercise test. CONCLUSIONS: These findings are important for clinicians evaluating symptoms of fatigue and myopathy in individuals with SCI.

Smoking and obstructive lung dysfunction in persons with chronic spinal cord injury.

BACKGROUND: Persons with higher-level spinal cord injury (SCI) have reduced vital capacity and increased risk of respiratory symptoms and illness, with smokers experiencing excess vital capacity losses. To date, obstructive lung dysfunction, the most prominent effect of smoking in the able-bodied population, has not been characterized in persons with SCI. OBJECTIVE: To determine whether smokers and/or nonsmokers with SCI are at increased risk to develop obstructive lung dysfunction, as measured by the ratio of forced expired volume in 1 second to forced vital capacity (FEV1/FVC). METHODS: Regression analyses on cross-sectional data from routine clinical testing of outpatients followed at the Bronx Veterans Affairs Medical Center in metropolitan New York (NY) and Rancho Los Amigos National Rehabilitation Center in metropolitan Los Angeles (LA) tested the relationship of FEV1/FVC (percentage of predicted normal value) to age, SCI characteristics, and smoking status. RESULTS: NY current smokers showed a significant (P < 0.01) excess decline in FEV1/FVC with increasing age; 35% fell below normal limits compared with 16% of NY former and never smokers. LA current smokers, who were generally younger and smoking less, showed a less clear age-related decline. Never smokers in NY or LA showed no age-related decline beyond that expected in the general population. Former smokers resembled never smokers, except that NY paraplegics showed borderline-significant (P = 0.09) excess age-related decline, which was less than that in NY current smokers. CONCLUSION: Smokers with SCI appeared to be at excessive risk for obstructive lung diseases. Smoking cessation appeared to reduce the risk substantially. Careful longitudinal studies are needed to confirm these findings.

Influence of hand-rim wheelchairs with rear suspension on seat forces and head acceleration during curb descent landings.

OBJECTIVE: Shocks and vibrations experienced while using a hand-rim wheelchair can contribute to discomfort, fatigue and injury. The aim of this study was to compare the seat forces and head accelerations experienced by manual wheelchair users during independent curb descent landings in a standard and 3 suspension-type rigid-frame wheelchairs. EXPERIMENTAL: repeated measures analysis of variance. PARTICIPANTS: Eight men with paraplegia due to spinal cord injury. METHODS: Participants performed independently-controlled curb descent maneuvers with 4 wheelchairs. The seat force and head accelerations were compared across wheelchairs. RESULTS: The suspension-type wheelchairs decreased the seat force and head accelerations by significantly (p < 0.05) extending the force rise time. Also, the seat force and head accelerations were inversely related to the seat force at initial contact. The monoshock-based suspension wheelchairs showed the least seat force and longest force rise time. CONCLUSION: Suspension systems result in softer landings by attenuating the magnitude and time duration of the force and reducing head accelerations. Hand-rim wheelchair users can also soften landings by utilizing a "pull-up" strategy that reduces the force and head accelerations. Softer landings can contribute to improved ride quality.

Effect of rear suspension and speed on seat forces and head accelerations experienced by manual wheelchair riders with spinal cord injury.

Whole-body shocks and vibrations experienced during manual wheelchair use can decrease an individual's comfort, increase the rate of fatigue, result in injury, and consequently limit mobility and community participation. We used a wheelchair-vibration simulator to examine whether the seat reaction forces experienced by wheelchair users were differentially influenced by wheelchair suspension, trunk-muscle innervations, and ground speed. We used wheelchairs instrumented with load cells and accelerometers to determine the forces transmitted from the seat frame and the head accelerations experienced by riders. We determined that self-selected speed, seat force, and head accelerations differed between subjects with and without trunk-muscle innervations and between rigid and suspension wheelchairs. Seat force and head accelerations were greatest in the rigid-frame wheelchair and lowest in the spring-type suspension-frame wheelchairs. Those participants without trunk-muscle innervations preferred slower speeds than those with trunk-muscle innervations. Forward head accelerations were greater in those without than with trunk-muscle innervations. Wheelchair rear-suspension systems may improve wheelchair mobility function in terms of comfort at higher velocity by minimizing the seat forces and head accelerations experienced by the riders, especially those with higher level spinal cord injury and diminished postural control.

Predictors of employment after liver transplantation.

Employment after orthotopic liver transplantation (OLT) indicates recipients' physical/psychosocial adjustment. Our aim was to determine clinical, socioeconomic and health-related quality of life parameters influencing employment after OLT. Questionnaire on demographics, medical conditions, alcohol and drug use before/after OLT, and a validated 12-Item Short Form Health Survey (SF-12) were mailed to 126 adult OLT patients. Stepwise logistic regression was conducted to identify best predictors of post-OLT employment. Among non-retirees, 49% were employed after OLT. The predictors of employment were: employment status, income, disability status before OLT and Model of End Stage Liver Disease score. These variables had prediction rate of 82%. Individuals working during the five yr prior to OLT were likely to return to work (p<0.0001), particularly those who held a job for >6 months prior to OLT (p<0.0001), income>$80 000 before OLT compared with <$30 000 (p=0.036). Patients receiving Social Security Insurance (SSI) payment for >or=6 months prior to OLT, were less likely to work (p=0.0005). Severity/duration of liver dysfunction prior to OLT did not correlate with employment. Sense of physical health was poorer in those employed after OLT than in unemployed (p=0.0003). Socioeconomic factors were the most important predictors of post-OLT employment.