Overall, this randomized clinical trial supports the use of a shoulder exercise and movement opti... more Overall, this randomized clinical trial supports the use of a shoulder exercise and movement optimization intervention in individuals with shoulder pain and spinal cord injury. The data for the subgroup receiving specific movement intervention instructions is particularly intriguing. These instructions are part of a clinical practice guideline from a consortium group. 6 Do the authors believe that going forward, these basic instructions would be a logical baseline intervention for these individuals, to which additional interventions could be compared individually or in combination? I thank PTJ for the opportunity to comment on this article, and I thank the authors for their important scientific contribution. I look forward to further contributions from these investigators and future studies considering comparative effectiveness of different treatment approaches to this important clinical problem.
Objectives: To compare prevalence of shoulder pain (SP) onset over 3 years for individuals with p... more Objectives: To compare prevalence of shoulder pain (SP) onset over 3 years for individuals with paraplegia from spinal cord injury who participate in one of two shoulder pain prevention program (SPPP) formats with that of a similar population without intervention, and to compare exercise adherence between two SPPP formats. Methods: The randomized clinical trial (compared to historical controls) included a volunteer sample of 100 individuals without SP at study entry. Eighty-seven participants returned for assessments at 18 and 36 months after study entry. Control group included 220 volunteers from a 3-year observational study with identical inclusion criteria. SPPPs included shoulder home exercises and recommendations to improve mobility techniques that are effective in reducing existing SP in this population. Participants were randomly assigned to receive either one instruction session and a refresher session 4 weeks later with a physical therapist or a 4-week series of 2-hour grou...
Archives of physical medicine and rehabilitation, Oct 22, 2016
To identify associations between objective and self-reported measures of physical activity (PA) a... more To identify associations between objective and self-reported measures of physical activity (PA) and relationships with depression and satisfaction with life (SWL) in persons with spinal cord injury (SCI). Retrospective, cross-sectional study of objectively measured wheelchair propulsion (WCP) from 2 studies in which an odometer was attached to participants' wheelchairs to record daily speed and distance. Self-reported data were collected in a separate study examining dyspnea, PA, mood, and SWL. Outpatient clinic in a rehabilitation center. Individuals (N=86) with traumatic SCI who use a manual wheelchair. Not applicable. Objective measures of PA included average daily distance and speed of WCP measured by an odometer. Self-report questionnaires included demographics, the 24-hour recall of transfers, Physical Activity Recall Assessment for People with SCI, the Patient Health Questionnaire-2 (PHQ-2) to document depressive symptoms, and the Satisfaction With Life Scale (SWLS). Both...
Objective To identify the prevalence of obesity in persons with chronic spinal cord injury (SCI),... more Objective To identify the prevalence of obesity in persons with chronic spinal cord injury (SCI), determine change in body mass index (BMI) over time, and identify impact of obesity on community mobility. Design Prospective three year longitudinal study. Setting Outpatient clinic of rehabilitation center. Participants Convenience sample of 222 persons with paraplegia between 2-20 years post SCI. Outcome Measures BMI at baseline and three years; community mobility (daily wheelchair propulsion distance and velocity, average number of daily transfers and depression raises). Results Participants were 34.1 (27.3, 40.3) years of age and median duration of SCI was 8.7 (3.2, 15.1) years. The SCI adjusted BMI classification identified 44% of participants as obese. BMI increased over time with 13% moving into a higher weight category. Median change in BMI was 0.46 (-0.92, 1.50) kg/m (2) (z = -2.684, P = 0.007), and increased at a rate of 0.15 kg/m(2)/yr. Average BMI was negatively correlated with daily wheelchair propulsion distance (r = -0.179, P = 0.009), however there was no significant relationship with velocity, number of daily transfers or depression raises. Conclusion The majority of participants with chronic SCI were overweight (23%) or obese (44%) and BMI increased by 0.46 kg/m(2) over three years. Those with higher BMIs pushed their wheelchairs shorter distances, but other mobility measures were not impacted by body weight. Continued mobility activities with increasing body weight can increase risk for shoulder injury. Identifying persons who are obese allows for directed and timely health and mobility intervention.
Shoulder loading during manual wheelchair propulsion (WCP) contributes to the development of shou... more Shoulder loading during manual wheelchair propulsion (WCP) contributes to the development of shoulder pain in individuals with spinal cord injury (SCI). To use regression analysis to investigate the relationships between the hand contact angle (location of the hand on the pushrim at initial contact and release during the push phase of the WCP cycle) with propulsion characteristics, pushrim forces, and shoulder kinetics during WCP in individuals with paraplegia. Biomechanical data were collected from 222 individuals (198 men and 24 women) with paraplegia from SCI during WCP on a stationary ergometer at a self-selected speed. The average age of participants was 34.7 years (±9.3), mean time since SCI was 9.3 years (±6.1), and average body weight was 74.4 kg (±15.9). The majority (n = 127; 56%) of participants had lower level paraplegia (T8 to L5) and 95 (42%) had high paraplegia (T2 to T7). Increased push arc (mean = 75.3°) was associated with greater velocity (R = 0.384, P < .001) and cycle distance (R = 0.658, P < .001) and reduced cadence (R = -0.419, P <.001). Initial contact angle and hand release angles were equally associated with cycle distance and cadence, whereas a more anterior release angle was associated with greater velocity (R = 0.372, P < .001). When controlling for body weight, a more posterior initial contact angle was associated with greater posterior shoulder net joint force (R = 0.229, P = .001) and greater flexor net joint moment (R = 0.204, P = .002), whereas a more anterior hand release angle was significantly associated with increased vertical (R = 0.270, P < .001) and greater lateral (R = .293, P < .001) pushrim forces; greater shoulder net joint forces in all 3 planes - posterior (R = 0.164, P = .015), superior (R = 0.176, P = .009), and medial (R = 0.284, P < .001); and greater external rotator (R = 0.176, P = .009) and adductor (R = 0.259, P = .001) net joint moments. Current clinical practice guidelines recommend using long, smooth strokes during manual WCP to reduce peak shoulder forces and to prevent shoulder pain development. The position of the hand at both initial contact and hand release must be considered in WCP training. It is recommended that participants should reach back to initiate contact with the pushrim to maximize push arc but avoid a more anterior hand position at release, because this could increase shoulder load during the push phase of WCP.
Frontiers in Bioengineering and Biotechnology, 2015
Car transfers and wheelchair (WC) loading are crucial for independent community participation in ... more Car transfers and wheelchair (WC) loading are crucial for independent community participation in persons with complete paraplegia from spinal cord injury, but are complex, physically demanding, and known to provoke shoulder pain. This study aimed to describe techniques and factors influencing car transfer and WC loading for individuals with paraplegia driving their own vehicles and using their personal WCs. Sedans were the most common vehicle driven (59%). Just over half (52%) of drivers place their right leg only into the vehicle prior to transfer. Overall, the leading hand was most frequently placed on the driver's seat (66%) prior to transfer and the trailing hand was most often place on the WC seat (48%). Vehicle height influenced leading hand placement but not leg placement such that drivers of higher profile vehicles were more likely to place their hand on the driver's seat than those who drove sedans. Body lift time was negatively correlated with level of injury and age and positively correlated with vehicle height and shoulder abduction strength. Drivers who transferred with their leading hand on the steering wheel had significantly higher levels of shoulder pain than those who placed their hand on the driver's seat or overhead. The majority of participants used both hands (62%) to load their WC frame, and overall, most loaded their frame into the back (62%) vs. the front seat. Sedan drivers were more likely to load their frame into the front seat than drivers of higher profile vehicles (53 vs. 17%). Average time to load the WC frame (10.7 s) was 20% of the total WC loading time and was not related to shoulder strength, frame weight, or demographic characteristics. Those who loaded their WC frame into the back seat had significantly weaker right shoulder internal rotators. Understanding car transfers and WC loading in independent drivers is crucial to prevent shoulder pain and injury and preserve community participation.
The increased demand on the upper limbs during manual wheelchair use results in a high prevalence... more The increased demand on the upper limbs during manual wheelchair use results in a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Because individuals with SCI are dependent on their upper extremities for mobility and daily activities, shoulder dysfunction can present a devastating loss of independence and decreased quality of life. Research on quantification of shoulder loading and muscular demands during wheelchair propulsion, self-transfers, weight-relief raises, and overhead activities is presented. This review examines evidence-based recommendations aimed at preserving shoulder function by addressing environmental factors related to ergonomics, equipment selection, and performance technique and personal factors related to enhancement of the load-bearing capacity of shoulder structure through strengthening and resistance training.
The highly repetitive and weight-bearing nature of wheelchair (WC) propulsion has been associated... more The highly repetitive and weight-bearing nature of wheelchair (WC) propulsion has been associated with shoulder pain among persons with spinal cord injury (SCI). Manipulation of WC seat position is believed to reduce the overall demand of WC propulsion. The objective of this investigation was to document the effect of fore-aft seat position on shoulder joint kinetics. Thirteen men with complete motor paraplegia propelled a test WC in 2 fore-aft seat positions during free, fast, and graded conditions. The seat-anterior position aligned the glenohumeral joint with the wheel axle and the seat-posterior position moved the glenohumeral joint 8 cm posteriorly. The right wheel of the test chair was instrumented to measure forces applied to the pushrim. An inverse dynamics algorithm was applied to calculate shoulder joint forces, external moments, and powers. For all test conditions, the superior component of the shoulder joint resultant force was significantly lower in the seat-posterior p...
The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high preval... more The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Lever-activated (LEVER) WCs have been presented as a less demanding alternative mode of manual WC propulsion. The objective of this study was to evaluate the shoulder muscle electromyographic activity and propulsion characteristics in manual WC users with SCI propelling a standard pushrim (ST) and LEVER WC design. Twenty men with complete injuries (ASIA A or B) and tetraplegia (C6, n = 5; C7, n = 7) or paraplegia (n = 8) secondary to SCI propelled ST and LEVER WCs at 3 propulsion conditions on a stationary ergometer: self-selected free, self-selected fast, and simulated graded resistance. Average velocity, cycle distance, and cadence; median and peak electromyographic intensity; and duration of electromyography of anterior deltoid, pectoralis major, supraspinatus, and infraspinatus muscles were compared between LEVER and...
Design, User Experience, and Usability. User Experience Design for Diverse Interaction Platforms and Environments, 2014
This paper outlines a design case study for Skyfarer, a mixed reality rehabilitation application ... more This paper outlines a design case study for Skyfarer, a mixed reality rehabilitation application developed for upper body exercise of individuals aging with disability. We describe how experience, experiential and participatory design methodologies were combined to develop a game, which was publicly exhibited at IEEE VR and ACM SIGGRAPH, and formally evaluated in a biomechanical study at Rancho Los Amigos National Rehabilitation Center RLANRC.
Chronic shoulder pain after SCI can be markedly reduced by using a relatively simple home exercis... more Chronic shoulder pain after SCI can be markedly reduced by using a relatively simple home exercise program coupled with assessment and modification of performance technique for several upper-extremity weight-bearing activities.
Archives of Physical Medicine and Rehabilitation, 2006
Objective: To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristic... more Objective: To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristics during bilateral forearm crutches and front-wheeled walker ambulation in persons with incomplete spinal cord injury (SCI). Design: Cross-sectional cohort study. Setting: Biomechanics laboratory. Participants: Fourteen adult volunteers with incomplete SCI recruited from outpatient rehabilitation hospital services. Interventions: Not applicable. Main Outcome Measure: Peak force, rate of loading, and force-time integral were compared for each component of the net 3D shoulder joint reaction force during ambulation with crutches and a walker. Stride characteristics were also compared between assistive device conditions. Results: The largest weight-bearing force was superiorly directed, followed by the posterior force. The superior joint force demonstrated a significantly higher peak and rate of loading during crutch walking (48.9N and 311.6N/s, respectively, vs 45.3N and 199.8N/s, respectively). The largest nonweight-bearing force was inferiorly directed with a significantly greater peak occurring during crutch ambulation (43.2N vs 23.6N during walker gait). Walking velocity and cadence were similar; however, stride length was significantly greater during crutch walking (62% vs 58% of normal). Conclusions: Shoulder joint forces during assisted ambulation were large. Crutch use increased the superior force but did not increase walking velocity.
Archives of Physical Medicine and Rehabilitation, 2009
J. Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and... more J. Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and push-rim activated power assisted wheelchair propulsion in persons with complete tetraplegia.
Background-The prevalence of women with spinal cord injury is increasing, and their unique attrib... more Background-The prevalence of women with spinal cord injury is increasing, and their unique attributes merit attention, specifically, shoulder strength and community wheelchair propulsion. Results-Shoulder torques were 62%-96% greater in men than women, average daily distance traveled was greater for men, and average speeds were similar. Conclusions-Community wheelchair propulsion speed was similar between men and women but men were significantly stronger, therefore daily mobility requires a higher relative effort for women's shoulder muscles. This demand may increase susceptibility to fatigue and development of shoulder pain.
Overall, this randomized clinical trial supports the use of a shoulder exercise and movement opti... more Overall, this randomized clinical trial supports the use of a shoulder exercise and movement optimization intervention in individuals with shoulder pain and spinal cord injury. The data for the subgroup receiving specific movement intervention instructions is particularly intriguing. These instructions are part of a clinical practice guideline from a consortium group. 6 Do the authors believe that going forward, these basic instructions would be a logical baseline intervention for these individuals, to which additional interventions could be compared individually or in combination? I thank PTJ for the opportunity to comment on this article, and I thank the authors for their important scientific contribution. I look forward to further contributions from these investigators and future studies considering comparative effectiveness of different treatment approaches to this important clinical problem.
Objectives: To compare prevalence of shoulder pain (SP) onset over 3 years for individuals with p... more Objectives: To compare prevalence of shoulder pain (SP) onset over 3 years for individuals with paraplegia from spinal cord injury who participate in one of two shoulder pain prevention program (SPPP) formats with that of a similar population without intervention, and to compare exercise adherence between two SPPP formats. Methods: The randomized clinical trial (compared to historical controls) included a volunteer sample of 100 individuals without SP at study entry. Eighty-seven participants returned for assessments at 18 and 36 months after study entry. Control group included 220 volunteers from a 3-year observational study with identical inclusion criteria. SPPPs included shoulder home exercises and recommendations to improve mobility techniques that are effective in reducing existing SP in this population. Participants were randomly assigned to receive either one instruction session and a refresher session 4 weeks later with a physical therapist or a 4-week series of 2-hour grou...
Archives of physical medicine and rehabilitation, Oct 22, 2016
To identify associations between objective and self-reported measures of physical activity (PA) a... more To identify associations between objective and self-reported measures of physical activity (PA) and relationships with depression and satisfaction with life (SWL) in persons with spinal cord injury (SCI). Retrospective, cross-sectional study of objectively measured wheelchair propulsion (WCP) from 2 studies in which an odometer was attached to participants' wheelchairs to record daily speed and distance. Self-reported data were collected in a separate study examining dyspnea, PA, mood, and SWL. Outpatient clinic in a rehabilitation center. Individuals (N=86) with traumatic SCI who use a manual wheelchair. Not applicable. Objective measures of PA included average daily distance and speed of WCP measured by an odometer. Self-report questionnaires included demographics, the 24-hour recall of transfers, Physical Activity Recall Assessment for People with SCI, the Patient Health Questionnaire-2 (PHQ-2) to document depressive symptoms, and the Satisfaction With Life Scale (SWLS). Both...
Objective To identify the prevalence of obesity in persons with chronic spinal cord injury (SCI),... more Objective To identify the prevalence of obesity in persons with chronic spinal cord injury (SCI), determine change in body mass index (BMI) over time, and identify impact of obesity on community mobility. Design Prospective three year longitudinal study. Setting Outpatient clinic of rehabilitation center. Participants Convenience sample of 222 persons with paraplegia between 2-20 years post SCI. Outcome Measures BMI at baseline and three years; community mobility (daily wheelchair propulsion distance and velocity, average number of daily transfers and depression raises). Results Participants were 34.1 (27.3, 40.3) years of age and median duration of SCI was 8.7 (3.2, 15.1) years. The SCI adjusted BMI classification identified 44% of participants as obese. BMI increased over time with 13% moving into a higher weight category. Median change in BMI was 0.46 (-0.92, 1.50) kg/m (2) (z = -2.684, P = 0.007), and increased at a rate of 0.15 kg/m(2)/yr. Average BMI was negatively correlated with daily wheelchair propulsion distance (r = -0.179, P = 0.009), however there was no significant relationship with velocity, number of daily transfers or depression raises. Conclusion The majority of participants with chronic SCI were overweight (23%) or obese (44%) and BMI increased by 0.46 kg/m(2) over three years. Those with higher BMIs pushed their wheelchairs shorter distances, but other mobility measures were not impacted by body weight. Continued mobility activities with increasing body weight can increase risk for shoulder injury. Identifying persons who are obese allows for directed and timely health and mobility intervention.
Shoulder loading during manual wheelchair propulsion (WCP) contributes to the development of shou... more Shoulder loading during manual wheelchair propulsion (WCP) contributes to the development of shoulder pain in individuals with spinal cord injury (SCI). To use regression analysis to investigate the relationships between the hand contact angle (location of the hand on the pushrim at initial contact and release during the push phase of the WCP cycle) with propulsion characteristics, pushrim forces, and shoulder kinetics during WCP in individuals with paraplegia. Biomechanical data were collected from 222 individuals (198 men and 24 women) with paraplegia from SCI during WCP on a stationary ergometer at a self-selected speed. The average age of participants was 34.7 years (±9.3), mean time since SCI was 9.3 years (±6.1), and average body weight was 74.4 kg (±15.9). The majority (n = 127; 56%) of participants had lower level paraplegia (T8 to L5) and 95 (42%) had high paraplegia (T2 to T7). Increased push arc (mean = 75.3°) was associated with greater velocity (R = 0.384, P < .001) and cycle distance (R = 0.658, P < .001) and reduced cadence (R = -0.419, P <.001). Initial contact angle and hand release angles were equally associated with cycle distance and cadence, whereas a more anterior release angle was associated with greater velocity (R = 0.372, P < .001). When controlling for body weight, a more posterior initial contact angle was associated with greater posterior shoulder net joint force (R = 0.229, P = .001) and greater flexor net joint moment (R = 0.204, P = .002), whereas a more anterior hand release angle was significantly associated with increased vertical (R = 0.270, P < .001) and greater lateral (R = .293, P < .001) pushrim forces; greater shoulder net joint forces in all 3 planes - posterior (R = 0.164, P = .015), superior (R = 0.176, P = .009), and medial (R = 0.284, P < .001); and greater external rotator (R = 0.176, P = .009) and adductor (R = 0.259, P = .001) net joint moments. Current clinical practice guidelines recommend using long, smooth strokes during manual WCP to reduce peak shoulder forces and to prevent shoulder pain development. The position of the hand at both initial contact and hand release must be considered in WCP training. It is recommended that participants should reach back to initiate contact with the pushrim to maximize push arc but avoid a more anterior hand position at release, because this could increase shoulder load during the push phase of WCP.
Frontiers in Bioengineering and Biotechnology, 2015
Car transfers and wheelchair (WC) loading are crucial for independent community participation in ... more Car transfers and wheelchair (WC) loading are crucial for independent community participation in persons with complete paraplegia from spinal cord injury, but are complex, physically demanding, and known to provoke shoulder pain. This study aimed to describe techniques and factors influencing car transfer and WC loading for individuals with paraplegia driving their own vehicles and using their personal WCs. Sedans were the most common vehicle driven (59%). Just over half (52%) of drivers place their right leg only into the vehicle prior to transfer. Overall, the leading hand was most frequently placed on the driver's seat (66%) prior to transfer and the trailing hand was most often place on the WC seat (48%). Vehicle height influenced leading hand placement but not leg placement such that drivers of higher profile vehicles were more likely to place their hand on the driver's seat than those who drove sedans. Body lift time was negatively correlated with level of injury and age and positively correlated with vehicle height and shoulder abduction strength. Drivers who transferred with their leading hand on the steering wheel had significantly higher levels of shoulder pain than those who placed their hand on the driver's seat or overhead. The majority of participants used both hands (62%) to load their WC frame, and overall, most loaded their frame into the back (62%) vs. the front seat. Sedan drivers were more likely to load their frame into the front seat than drivers of higher profile vehicles (53 vs. 17%). Average time to load the WC frame (10.7 s) was 20% of the total WC loading time and was not related to shoulder strength, frame weight, or demographic characteristics. Those who loaded their WC frame into the back seat had significantly weaker right shoulder internal rotators. Understanding car transfers and WC loading in independent drivers is crucial to prevent shoulder pain and injury and preserve community participation.
The increased demand on the upper limbs during manual wheelchair use results in a high prevalence... more The increased demand on the upper limbs during manual wheelchair use results in a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Because individuals with SCI are dependent on their upper extremities for mobility and daily activities, shoulder dysfunction can present a devastating loss of independence and decreased quality of life. Research on quantification of shoulder loading and muscular demands during wheelchair propulsion, self-transfers, weight-relief raises, and overhead activities is presented. This review examines evidence-based recommendations aimed at preserving shoulder function by addressing environmental factors related to ergonomics, equipment selection, and performance technique and personal factors related to enhancement of the load-bearing capacity of shoulder structure through strengthening and resistance training.
The highly repetitive and weight-bearing nature of wheelchair (WC) propulsion has been associated... more The highly repetitive and weight-bearing nature of wheelchair (WC) propulsion has been associated with shoulder pain among persons with spinal cord injury (SCI). Manipulation of WC seat position is believed to reduce the overall demand of WC propulsion. The objective of this investigation was to document the effect of fore-aft seat position on shoulder joint kinetics. Thirteen men with complete motor paraplegia propelled a test WC in 2 fore-aft seat positions during free, fast, and graded conditions. The seat-anterior position aligned the glenohumeral joint with the wheel axle and the seat-posterior position moved the glenohumeral joint 8 cm posteriorly. The right wheel of the test chair was instrumented to measure forces applied to the pushrim. An inverse dynamics algorithm was applied to calculate shoulder joint forces, external moments, and powers. For all test conditions, the superior component of the shoulder joint resultant force was significantly lower in the seat-posterior p...
The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high preval... more The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Lever-activated (LEVER) WCs have been presented as a less demanding alternative mode of manual WC propulsion. The objective of this study was to evaluate the shoulder muscle electromyographic activity and propulsion characteristics in manual WC users with SCI propelling a standard pushrim (ST) and LEVER WC design. Twenty men with complete injuries (ASIA A or B) and tetraplegia (C6, n = 5; C7, n = 7) or paraplegia (n = 8) secondary to SCI propelled ST and LEVER WCs at 3 propulsion conditions on a stationary ergometer: self-selected free, self-selected fast, and simulated graded resistance. Average velocity, cycle distance, and cadence; median and peak electromyographic intensity; and duration of electromyography of anterior deltoid, pectoralis major, supraspinatus, and infraspinatus muscles were compared between LEVER and...
Design, User Experience, and Usability. User Experience Design for Diverse Interaction Platforms and Environments, 2014
This paper outlines a design case study for Skyfarer, a mixed reality rehabilitation application ... more This paper outlines a design case study for Skyfarer, a mixed reality rehabilitation application developed for upper body exercise of individuals aging with disability. We describe how experience, experiential and participatory design methodologies were combined to develop a game, which was publicly exhibited at IEEE VR and ACM SIGGRAPH, and formally evaluated in a biomechanical study at Rancho Los Amigos National Rehabilitation Center RLANRC.
Chronic shoulder pain after SCI can be markedly reduced by using a relatively simple home exercis... more Chronic shoulder pain after SCI can be markedly reduced by using a relatively simple home exercise program coupled with assessment and modification of performance technique for several upper-extremity weight-bearing activities.
Archives of Physical Medicine and Rehabilitation, 2006
Objective: To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristic... more Objective: To compare 3-dimensional (3D) shoulder joint reaction forces and stride characteristics during bilateral forearm crutches and front-wheeled walker ambulation in persons with incomplete spinal cord injury (SCI). Design: Cross-sectional cohort study. Setting: Biomechanics laboratory. Participants: Fourteen adult volunteers with incomplete SCI recruited from outpatient rehabilitation hospital services. Interventions: Not applicable. Main Outcome Measure: Peak force, rate of loading, and force-time integral were compared for each component of the net 3D shoulder joint reaction force during ambulation with crutches and a walker. Stride characteristics were also compared between assistive device conditions. Results: The largest weight-bearing force was superiorly directed, followed by the posterior force. The superior joint force demonstrated a significantly higher peak and rate of loading during crutch walking (48.9N and 311.6N/s, respectively, vs 45.3N and 199.8N/s, respectively). The largest nonweight-bearing force was inferiorly directed with a significantly greater peak occurring during crutch ambulation (43.2N vs 23.6N during walker gait). Walking velocity and cadence were similar; however, stride length was significantly greater during crutch walking (62% vs 58% of normal). Conclusions: Shoulder joint forces during assisted ambulation were large. Crutch use increased the superior force but did not increase walking velocity.
Archives of Physical Medicine and Rehabilitation, 2009
J. Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and... more J. Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and push-rim activated power assisted wheelchair propulsion in persons with complete tetraplegia.
Background-The prevalence of women with spinal cord injury is increasing, and their unique attrib... more Background-The prevalence of women with spinal cord injury is increasing, and their unique attributes merit attention, specifically, shoulder strength and community wheelchair propulsion. Results-Shoulder torques were 62%-96% greater in men than women, average daily distance traveled was greater for men, and average speeds were similar. Conclusions-Community wheelchair propulsion speed was similar between men and women but men were significantly stronger, therefore daily mobility requires a higher relative effort for women's shoulder muscles. This demand may increase susceptibility to fatigue and development of shoulder pain.
Uploads
Papers by Lisa L Haubert