Nathan S. Hogaboom

The Relationship between Independent Transfer Skills and Upper Limb Kinetics in Wheelchair Users

Transfers are one of the most physically demanding wheelchair activities. The purpose of this study was to determine if using proper transfer skills as measured by the Transfer Assessment Instrument (TAI) is associated with reduced loading on the upper extremities. Twenty-three wheelchair users performed transfers to a level-height bench while a series of forces plates, load cells, and a motion capture system recorded the biomechanics of their natural transferring techniques. Their transfer skills were simultaneously evaluated by two study clinicians using the TAI. Logistic regression and multiple linear regression models were used to determine the relationships between TAI scores and the kinetic variables on both arms across all joints. The results showed that the TAI measured transfer skills were closely associated with the magnitude and timing of joint moments (P < .02, model R2 values ranged from 0.27 to 0.79). Proper completion of the skills which targeted the trailing arm was associated with lower average resultant moments and rates of rise of resultant moments at the trailing shoulder and/or elbow. Some skills involving the leading side had the effect of increasing the magnitude or rate loading on the leading side. Knowledge of the kinetic outcomes associated with each skill may help users to achieve the best load-relieving effects for their upper extremities.

Computer keyboarding biomechanics and acute changes in median nerve indicative of carpal tunnel syndrome

BACKGROUND Carpal tunnel syndrome is a common and costly peripheral neuropathy. Occupations requiring repetitive, forceful motions of the hand and wrist may play a role in the development of carpal tunnel syndrome. Computer keyboarding is one such task, and has been associated with upper-extremity musculoskeletal disorder development. The purpose of this study was to determine whether continuous keyboarding can cause acute changes in the median nerve and whether these changes correlate with wrist biomechanics during keyboarding. METHODS A convenience sample of 37 healthy individuals performed a 60-minute typing task. Ultrasound images were collected at baseline, after 30 and 60 min of typing, then after 30 min of rest. Kinematic data were collected during the typing task. Variables of interest were median nerve cross-sectional area, flattening ratio, and swelling ratio at the pisiform; subject characteristics (age, gender, BMI, wrist circumference, typing speed) and wrist joint angles. FINDINGS Cross-sectional area and swelling ratio increased after 30 and 60 min of typing, and then decreased to baseline after 30 min of rest. Peak ulnar deviation contributed to changes in cross-sectional area after 30 min of typing. INTERPRETATION Results from this study confirmed a typing task causes changes in the median nerve, and changes are influenced by level of ulnar deviation. Furthermore, changes in the median nerve are present until cessation of the activity. While it is unclear if these changes lead to long-term symptoms or nerve injury, their existence adds to the evidence of a possible link between carpal tunnel syndrome and keyboarding.

Transfer component skill deficit rates among Veterans who use wheelchairs

The purpose of this study was to quantify the deficit rates for transfer component skills in a Veteran cohort and explore the relationship between deficit rates and subject characteristics. Seventy-four men and 18 women performed up to four transfers independently from their wheelchair to a mat table while a therapist evaluated their transfer techniques using the Transfer Assessment Instrument. The highest deficit rates concerned the improper use of handgrips (63%). Other common problems included not setting the wheelchair up at the proper angle (50%) and not removing the armrest (58%). Veterans over 60 yr old and Veterans with moderate shoulder pain were more likely to set up their wheelchairs inappropriately than younger Veterans (p = 0.003) and Veterans with mild shoulder pain (p = 0.004). Women were less likely to remove their armrests than men (p = 0.03). Subjects with disabilities other than spinal cord injury were less inclined to set themselves up for a safe and easy transfer than the subjects with spinal cord injury (p ≤ 0.001). The results provide insight into the disparities present in transfer skills among Veterans and will inform the development of future transfer training programs both within and outside of the Department of Veterans Affairs.

Ultrasonographic Median Nerve Changes After Repeated Wheelchair Transfers in Persons With Paraplegia: Relationship With Subject Characteristics and Transfer Skills

Wheelchair users with spinal cord injuries are susceptible to peripheral neuropathies from overuse, yet no studies have established a relationship between median neuropathy and wheelchair transfers. A more thorough understanding of how transfers and technique contribute to pathologic conditions may guide interventions that curtail its development.

Evacuation preparedness in full-time wheelchair users with spinal cord injury

Abstract Objective To analyze and evaluate the efficacy of evacuation plans described by individuals with spinal cord injury (SCI). Design Descriptive study from a convenience sample. Setting Outpatient population center in Pittsburgh, PA, USA. Methods Twenty-one individuals with SCI who previously indicated that they had a plan of evacuation from either their homes, places of work, or towns/cities were contacted via telephone and asked to describe their evacuation plans. The number of critical elements (scale of 0–10 with 10 indicating a more thorough plan) and assistive technology (AT) devices were recorded. Outcome measures The number of critical elements (scale of 0–10 with 10 indicating a more thorough plan) and AT devices were recorded. Results Median home and town/city evacuation scores were both 3.00 (ranges: 1.0–4.0 and 0.0–8.0, respectively). Median evacuation scores of individuals with paraplegia were higher in home (P = 0.05, r = 0.44) and town/city (P = 0.045, r = 0.63) than individuals with tetraplegia. Median evacuation scores of subjects who were employed were higher in home (P = 0.036, r = 0.47) and town/city (P = 0.064, r = 0.59) than unemployed. Conclusion Low scores indicate that individuals with SCI who believe that they have plans are not adequately prepared for an emergency evacuation. Interventions are needed to improve evacuation readiness and lack of preparedness in a catastrophe should be considered by emergency personnel when responding.

Acute Response of the Infraspinatus and Biceps Tendons to Pitching in Youth Baseball

Purpose Youth baseball frequently results in repetitive strain injuries. Quantitative ultrasound allows real-time imaging with the ability to identify acute markers of tendon change. The study objective was to determine acute quantitative ultrasound changes in the long head of the biceps and infraspinatus tendons of the throwing and nonthrowing shoulders during a pitching performance. We hypothesized the tendons of the pitching arm would exhibit an increased width and decreased echogenicity after pitching and that tendons of the nonpitching arm would not demonstrate such changes. Methods Fifty youth baseball players, ages 9–14 yr, engaged in a simulated pitching performance that consisted of 50 pitches. Subjects underwent serial quantitative ultrasound imaging of the infraspinatus and the long head of the biceps before pitching and after 25 and 50 pitches were thrown. Results Testing of the change in tendon width revealed the infraspinatus (0.21 mm) and long head of the biceps tendons (0.18 mm) in the throwing shoulder had statistically significant increases (P = 0.03) in tendon width as an acute response to throwing 50 pitches, without such changes in the nonthrowing shoulder (P > 0.05). No tendon width change was found at 25 pitches in either arm or tendon (P > 0.05). No associated changes in echogenicity were found at any time point (P > 0.05). Conclusion The results of this study suggest that pitching acutely increases tendon width in two biomechanically important tendons of the shoulder as early as the 50 pitch mark. This change could be a normal physiological response or a potential warning sign of future pathology and requires further study.

Relationship between linear velocity and tangential push force while turning to change the direction of the manual wheelchair.

Abstract Wheelchair propulsion is a major cause of upper limb pain and injuries for manual wheelchair users with spinal cord injuries (SCIs). Few studies have investigated wheelchair turning biomechanics on natural ground surfaces. The purpose of this study was to investigate the relationship between tangential push force and linear velocity of the wheelchair during the turning portions of propulsion. Using an instrumented handrim, velocity and push force data were recorded for 25 subjects while they propel their own wheelchairs on a concrete floor along a figure-eight-shaped course at a maximum velocity. The braking force (1.03 N) of the inside wheel while turning was the largest of all other push forces (p<0.05). Larger changes in squared velocity while turning were significantly correlated with higher propulsive and braking forces used at the pre-turning, turning, and post-turning phases (p<0.05). Subjects with less change of velocity while turning needed less braking force to maneuver themselves successfully and safely around the turns. Considering the magnitude and direction of tangential force applied to the wheel, it seems that there are higher risks of injury and instability for upper limb joints when braking the inside wheel to turn. The results provide insight into wheelchair setup and mobility skills training for wheelchair users.

Longitudinal Prediction of Quality-of-Life Scores and Locomotion in Individuals With Traumatic Spinal Cord Injury

OBJECTIVES To examine (1) differences in quality-of-life scores for groups based on transitions in locomotion status at 1, 5, and 10 years postdischarge in a sample of people with spinal cord injury (SCI); and (2) whether demographic factors and transitions in locomotion status can predict quality-of-life measures at these time points. DESIGN Retrospective case study of the National SCI Database. SETTING Model SCI Systems Centers. PARTICIPANTS Individuals with SCI (N=10,190) from 21 SCI Model Systems Centers, identified through the National SCI Model Systems Centers database between the years 1985 and 2012. Subjects had FIM (locomotion mode) data at discharge and at least 1 of the following: 1, 5, or 10 years postdischarge. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES FIM-locomotion mode; Severity of Depression Scale; Satisfaction With Life Scale; and Craig Handicap Assessment and Reporting Technique. RESULTS Participants who transitioned from ambulation to wheelchair use reported lower participation and life satisfaction, and higher depression levels (P<.05) than those who maintained their ambulatory status. Participants who transitioned from ambulation to wheelchair use reported higher depression levels (P<.05) and no difference for participation (P>.05) or life satisfaction (P>.05) compared with those who transitioned from wheelchair to ambulation. Demographic factors and locomotion transitions predicted quality-of-life scores at all time points (P<.05). CONCLUSIONS The results of this study indicate that transitioning from ambulation to wheelchair use can negatively impact psychosocial health 10 years after SCI. Clinicians should be aware of this when deciding on ambulation training. Further work to characterize who may be at risk for these transitions is needed.

Investigating the Efficacy of Web-Based Transfer Training on Independent Wheelchair Transfers Through Randomized Controlled Trials

OBJECTIVES To determine the efficacy of a web-based transfer training module at improving transfer technique across 3 groups: web-based training, in-person training (current standard of practice), and a waitlist control group (WLCG); and secondarily, to determine subject factors that can be used to predict improvements in transfer ability after training. DESIGN Randomized controlled trials. SETTING Summer and winter sporting events for disabled veterans. PARTICIPANTS A convenience sample (N=71) of manual and power wheelchair users who could transfer independently. INTERVENTIONS An individualized, in-person transfer training session or a web-based transfer training module. The WLCG received the web training at their follow-up visit. MAIN OUTCOME MEASURE Transfer Assessment Instrument (TAI) part 1 score was used to assess transfers at baseline, skill acquisition immediately posttraining, and skill retention after a 1- to 2-day follow-up period. RESULTS The in-person and web-based training groups improved their median (interquartile range) TAI scores from 7.98 (7.18-8.46) to 9.13 (8.57-9.58; P<.01), and from 7.14 (6.15-7.86) to 9.23 (8.46-9.82; P<.01), respectively, compared with the WLCG that had a median score of 7.69 for both assessments (baseline, 6.15-8.46; follow-up control, 5.83-8.46). Participants retained improvements at follow-up (P>.05). A lower initial TAI score was found to be the only significant predictor of a larger percent change in TAI score after receiving training. CONCLUSIONS Transfer training can improve technique with changes retained within a short follow-up window, even among experienced wheelchair users. Web-based transfer training demonstrated comparable improvements to in-person training. With almost half of the United States population consulting online resources before a health care professional, web-based training may be an effective method to increase knowledge translation.

Cross-Sectional Investigation of Acute Changes in Ultrasonographic Markers for Biceps and Supraspinatus Tendon Degeneration After Repeated Wheelchair Transfers in People With Spinal Cord Injury.

ObjectiveThe objectives of this work were to investigate how wheelchair transfers influence acute changes in ultrasound markers for biceps and supraspinatus tendon degeneration and to determine how such changes correlate with transfer technique and demographic characteristics. DesignParticipants underwent quantitative ultrasound examinations for markers of biceps and supraspinatus tendon degeneration (tendon width, echogenicity, variance, and contrast) before and after a stressful repeated-transfers protocol. The Transfer Assessment Instrument was completed for each participant to identify transfer skills. Linear regression tested whether demographics and transfer skills correlated with ultrasound measures. ResultsSixty-two wheelchair users with spinal cord injury were included (39 with paraplegia and 23 with tetraplegia). Biceps tendon width increased after repeated transfers (P < 0.001). Participants with greater body weight experienced greater increases in biceps width after transfers (&bgr; = 0.109, P < 0.05). Skills evaluating body position relative to the target surface and safe and stable hand and arm positions affected changes in biceps and supraspinatus width and echogenicity (P < 0.05). ConclusionsRepeated transfers caused measurable changes in biceps tendon width in a subset of participants. Changes in biceps and supraspinatus ultrasound measures were related to body weight and performance of specific transfer skills. Further testing is needed to confirm whether the clinical meaning of the observed relationships and whether using certain transfer skills and reducing body weight can attenuate the development of tendinopathy.