Biomedical subjects

Mary M Rodgers

Publications and source records attributed to Mary M Rodgers.

8 recordsLinked to original sources

PubMed2007

Determinants of walking function after stroke: differences by deficit severity.

OBJECTIVES: To investigate the relationship of cardiovascular fitness (Vo(2)peak), neurologic deficits in balance and leg strength, and body composition to ambulatory function after stroke and to determine whether these relationships differ between those with milder versus more severe gait deficits. DESIGN: Cross-sectional correlation study. SETTING: Outpatient clinic of an academic medical center. PARTICIPANTS: Seventy-four people (43 men, 31 women; mean age +/- standard deviation, 64+/-10y) with chronic hemiparetic stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Thirty-foot (9.1-m) walk velocity, 6-minute walk distance, Vo(2)peak, Berg Balance Scale score, bilateral quadriceps eccentric torque, total and regional lean mass, and percentage of fat mass. RESULTS: Short-distance walking correlated significantly with cardiovascular fitness, balance, paretic leg strength, nonparetic leg strength, percentage of body fat, and paretic lean mass but not with nonparetic lean mass. Long-distance walking correlated significantly with cardiovascular fitness, balance, paretic leg strength, nonparetic leg strength, and paretic lean mass but not with percentage of body fat or nonparetic lean mass. Stepwise regression showed that cardiovascular fitness, balance, and paretic leg strength were independently associated with long-distance walking (r(2)=.60, P<.001). Variance in long-distance walking was largely explained by balance for those who walked more slowly (<.48m/s) for short distances (r(2)=.42, P<.001) and by cardiovascular fitness for those who walked more quickly (>.48m/s) for short distances (r(2)=.26, P=.003). CONCLUSIONS: Short-distance walking after stroke is related to balance, cardiovascular fitness, and paretic leg strength. Long-distance walking ability differs by gait deficit severity, with balance more important in those who walk more slowly and cardiovascular fitness playing a greater role in those who walk more quickly. Improved understanding of the factors that predict ambulatory function may assist the design of individualized rehabilitation strategies across the spectrum of gait deficit severity in those with hemiparetic stroke.

Adult↗

PubMed2005

Scapular kinematics during transfers in manual wheelchair users with and without shoulder impingement.

BACKGROUND: Scapular function during humeral elevation has been reported in groups with and without shoulder impingement pathology. To date, no one has assessed scapular kinematics during upper extremity loaded tasks that manual wheelchair users must perform on a daily basis. Therefore, the objective of this study was to compare scapular kinematics and muscle activation patterns during two different wheelchair transfers in groups of manual wheelchair users with and without shoulder impingement. METHODS: A case controlled study of manual wheelchair users, with and without shoulder impingement was performed. Twenty-three male manual wheelchair users (13 without shoulder impingement, 10 with shoulder impingement) performed transfers toward the involved or dominant limb (lead limb transfer) and away from the instrumented limb (trail limb transfer). Position and orientation measures of the thorax, scapula and humerus were obtained using an electromagnetic tracking system. Muscle activity data were collected using telemetered electromyography. Each subject performed three trials of wheelchair transfers to each side. FINDINGS: Manual wheelchair users with impingement performed transfers with reduced thoracic flexion, increased scapular internal rotation, and increased humeral internal rotation as compared to those without impingement. Differences were found between the tasks in the scapular motions and EMG amplitude. Trail limb transfer presented with reduced scapular upward rotation and posterior tip as compared to the lead limb transfer task. Increased muscle activity for the lower trapezius and serratus anterior muscles was demonstrated in the trail limb transfer. INTERPRETATION: This study provides the first kinematic description of scapular kinematics during transfer tasks. Shoulder impingement and direction of transfer does affect transfer task performance in manual wheelchair users. Scapular kinematics and muscle patterns during transfers may predispose manual wheelchair users to the development of shoulder pathology.

Adult↗

PubMed2004

Prevalence and identification of shoulder pathology in athletic and nonathletic wheelchair users with shoulder pain: A pilot study.

Although many wheelchair users report shoulder pain, the prevalence of specific pathologies remains controversial. Rotator cuff impingement, glenohumeral instability, and biceps tendonitis have been stated as the most commonly found pathology. This study investigated the prevalence and identity of shoulder pathology in athletic and nonathletic manual wheelchair users (MWCUs). Fifty-two MWCUs (26 athletes, 26 nonathletes) completed a survey regarding the nature of their injury, sports involvement, history, and presence of current and/or past shoulder pathology. Subjects currently experiencing shoulder pain underwent a clinical examination of both shoulders. Analysis of variance (p <or=0.05) determined if differences existed between the groups in demographic variables, history of shoulder pain, and clinical evaluation measures in those with shoulder pain. Chi-squared (p <or=0.05) analysis verified the frequency distribution and association by groups and involved limbs for the clinical shoulder test measures. No difference was found in the incidence of shoulder pain, past or present, between athletes and nonathletes. Collectively, 61.5% (32/52) of the subjects reported experiencing shoulder pain, with 29% reporting shoulder pain at the present time. Years since onset of disability (p = 0.01) and duration of wheelchair use (p = 0.01) were found to be greater in individuals who reported a history of shoulder pain. Of the painful shoulders tested, 44% revealed clinical signs and symptoms of rotator cuff impingement, while 50% revealed signs of biceps tendonitis. Instability was found in 28% of the painful shoulders. These findings indicate that involvement in athletics neither increases nor decreases the risk of shoulder pain in the manual wheelchair population. Bicipital tendonitis with impingement syndrome was the most common pathology.

Adult↗

PubMed2004

The biomechanics of wheelchair propulsion in individuals with and without upper-limb impairment.

We used an instrumented wheelchair ergometer and 3D motion analysis system to collect joint kinematic and temporal data, as well as hand rim and joint kinetics, in 47 manual wheelchair users (MWCUs) (15 with upper-limb impairment and 32 without upper-limb impairment). The group with upper-limb impairment propelled with a higher stroke frequency and reduced hand-rim contact time, and smaller peak joint angles and joint excursion of the wrist, elbow, and shoulder during the contact phase. They also propelled with a reduced power output and reduced hand-rim propulsive and resultant forces, moments, and joint compressive forces. We concluded that these kinematic and kinetic strategies might be a mechanism for allowing MWCUs with upper-limb impairment to remain independent. Additionally, the reduced joint excursion and reduced magnitude of forces may protect them from the development of secondary upper-limb pathologies.

Adult↗

PubMedDate not supplied

Upper-limb fatigue-related joint power shifts in experienced wheelchair users and nonwheelchair users.

This paper evaluates power transfer or shifting across upper-limb segments, resulting from fatigue-inducing wheelchair propulsion. Nineteen manual wheelchair users (WCUs) and ten nonwheelchair users (NUs) participated in this study. Subjects propelled an instrumented wheelchair ergometer at a workload corresponding to 75% of the peak oxygen uptake attained during a maximal-graded exercise tolerance test. Subjects were required to propel the wheelchair for as long as they could at a constant velocity of 3 km/h (32 rpm). The test was terminated when subjects could no longer maintain the target velocity. Peak Performance video-capture system was used to determine upper-limb kinematics. Handrim forces and joint kinematics were used to calculate joint moments and power with the use of an inverse dynamics approach. Results showed that with fatigue, joint power shifts from the shoulder joint to the elbow and wrist joints. Implications for joint injury and propulsion efficiency are discussed.

Adult↗

PubMedDate not supplied

Development of a functional assessment measure for manual wheelchair users.

This investigation developed the Wheelchair Users Functional Assessment (WUFA). Because no functional outcome tools exist that include many of the daily activities that are needed to be independent by individuals using manual wheelchairs, development of an appropriate tool was deemed important. Although the Functional Independence Measure (FIM) can be used to assess disability in those using a wheelchair, it only measures some aspects of basic activities of daily living (ADLs) and does not measure community independence. Therefore, both basic activities and community activities were included in the new tool. A panel of six rehabilitation experts, with input from manual wheelchair users, determined content of the instrument. The resulting WUFA scale includes 13 items. Interrater reliability and stability were established with the calculation of an intraclass correlation coefficient (ICC). ICC for interrater reliability was 0.96 and ICC for stability was 0.78. Further analysis was performed on the internal consistency of the 13-item tool using a sample of 101 tested subjects. This analysis was done using a Cronbach's Alpha. Results indicated excellent internal consistency of the 13 items. The standardized coefficient alpha was 0.96. The WUFA was shown to have content validity, promising interrater reliability and stability, and good internal consistency. Further research is warranted to determine the tool's sensitivity and capability to discriminate between levels of functional independence.

Activities of Daily Living↗

PubMedDate not supplied

Improved upper-body endurance following a 12-week home exercise program for manual wheelchair users.

This study determined if a 12-week monitored home exercise program would improve cardiorespiratory endurance in a heterogeneous group of manual wheelchair users, which incorporated subsets of individuals with and without upper-limb impairment. Twenty-seven subjects made up two groups of manual wheelchair users: 20 without upper-limb impairment and 7 with upper-limb impairment. Subjects completed wheelchair ergometer tests using a 1 min JUMP protocol that resulted in volitional exhaustion in 6 to 12 min. Following a recovery period (time > 30 min), subjects completed subsequent constant work rate endurance tests to exhaustion at a power output corresponding to 60% of the maximum attained on the JUMP test. Subjects then underwent 12 weeks of simulated wheelchair rolling exercise using elastic straps positioned to mimic the motion of propulsion. JUMP and constant work rate tests were performed before training and after 6 and 12 weeks of exercise. Oxygen consumption (VO2) increased from rest to peak exercise in both groups and was significantly (p < 0.016) higher at peak for subjects without upper-limb impairment than for those with upper-limb impairment. Heart rate (HR) responses between the groups were similar. No significant differences in peak VO2, anaerobic threshold, or peak HR were observed at 6 or 12 weeks of the training program. Substantial improvement (p < 0.001) in maximum constant work rate tests time (10.37 +/- 2.79 min) was noted at 6 and 12 weeks, with no significant difference between 6 and 12 weeks and no significant intergroup difference. Results of this study indicated that simulated propulsion exercise endurance was improved as a result of the home exercise program.

Adult↗

PubMedDate not supplied

Reliability of biomechanical variables during wheelchair ergometry testing.

Wheelchair ergometer testing is used to characterize wheelchair propulsion mechanics. The reliability of kinematic and kinetic measures has not been investigated for wheelchair ergometer testing. In this study, test-retest reliability of biomechanical measurements on a wheelchair ergometer was determined during a submaximal endurance test. Ten nondisabled subjects (seven male, three female), inexperienced in wheelchair propulsion, completed three separate submaximal fatigue tests. An instrumented wheelchair ergometer was used to measure handrim kinetics while three-dimensional kinematic data were collected. Analysis of variance was used to determine if measurement differences existed across the tests. Intraclass correlation coefficients (ICC) were calculated to determine the reliability of the measurements. The majority of handrim and temporal variables were found to be reliable. Joint kinematic variables were less reliable, especially those involving wrist movements in the fatigued state. It was concluded that most biomechanical variables obtained during wheelchair ergometry were reliable.

Adult↗