S. van Drongelen

Upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using persons with a spinal cord injury

Study design:Prospective cohort study.Objectives:To study upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using subjects with a spinal cord injury (SCI) and its relation with lesion characteristics, muscle strength and functional outcome.Setting:Eight rehabilitation centers with an SCI unit in the Netherlands.Methods:Using a questionnaire, number, frequency and seriousness of musculoskeletal pain complaints of the upper extremity were measured. A pain score for the wrist, elbow and shoulder joints was calculated by multiplying the seriousness by the frequency of pain complaints. An overall score was obtained by adding the scores of the three joints of both upper extremities. Muscle strength was determined by manual muscle testing. The motor score of the functional independence measure provided a functional outcome. All outcomes were obtained at four test occasions during and 1 year after rehabilitation.Results:Upper extremity pain and shoulder pain decreased over time (30%) during the latter part of in-patient rehabilitation (P<0.001). Subjects with tetraplegia (TP) showed more musculoskeletal pain than subjects with paraplegia (PP) (P<0.001). Upper extremity pain and shoulder pain were significantly inversely related to functional outcome (P<0.001). Muscle strength was significantly inversely related to shoulder pain (P<0.001). Musculoskeletal pain at the beginning of rehabilitation and BMI were strong predictors for pain 1 year after in-patient rehabilitation (P<0.001).Conclusions:Subjects with TP are at a higher risk for upper extremity musculoskeletal pain and for shoulder pain than subjects with PP. Higher muscle strength and higher functional outcome are related to fewer upper extremity complaints.

Is effective force application in handrim wheelchair propulsion also efficient

BACKGROUND Efficiency in manual wheelchair propulsion is low, as is the fraction of the propulsion force that is attributed to the moment of propulsion of the wheelchair. In this study we tested the hypothesis that a tangential propulsion force direction leads to an increase in physiological cost, due to (1) the sub-optimal use of elbow flexors and extensors, and/or (2) the necessity of preventing of glenohumeral subluxation. METHODS Five able-bodied and 11 individuals with a spinal cord injury propelled a wheelchair while kinematics and kinetics were collected. The results were used to perform inverse dynamical simulations with input of (1) the experimentally obtained propulsion force, and (2) only the tangential component of that force. FINDINGS In the tangential force condition the physiological cost was over 30% higher, while the tangential propulsion force was only 75% of the total experimental force. According to model estimations, the tangential force condition led to more co-contraction around the elbow, and a higher power production around the shoulder joint. The tangential propulsion force led to a significant, but small 4% increase in necessity for the model to compensate for glenohumeral subluxation, which indicates that this is not a likely cause of the decrease in efficiency. INTERPRETATION The present findings support the hypothesis that the observed force direction in wheelchair propulsion is a compromise between efficiency and the constraints imposed by the wheelchair-user system. This implies that training should not be aimed at optimization of the propulsion force, because this may be less efficient and more straining for the musculoskeletal system.

Load on the shoulder complex during wheelchair propulsion and weight relief lifting

BACKGROUND This study focuses on the relationship between overuse in association with wheelchair activities of daily living and risks for osteoarthrosis in the acromioclavicular and sternoclavicular joints. The aim is to quantify the joint moments and joint reaction forces in all three joints of the shoulder complex during wheelchair-related activities of daily living. METHODS A convenience sample of 17 subjects performed two tasks (wheelchair propulsion and weight relief lifting). Three-dimensional kinematics and kinetics were measured and position and force data were used as input for a musculoskeletal model of the arm and shoulder. Output variables of the model were the moments and the joint reaction forces on the sternoclavicular, acromioclavicular and glenohumeral joints. FINDINGS Moments on the sternoclavicular joint were higher than on the acromioclavicular and glenohumeral joint, but the joint reaction forces on the sternoclavicular and acromioclavicular joints were only one third of those on the glenohumeral joint (peak forces around 96N compared to 315N for wheelchair propulsion and around 330N compared to 1288N for weight relief lifting). INTERPRETATION Based on the results found in this study, net joint moments are likely a better measure to describe the load on the acromioclavicular and sternoclavicular joints due to the passive stabilization. Prospective studies on wheelchair overuse injuries should also look at the acromioclavicular and sternoclavicular joints since the load of wheelchair tasks might be a risk factor for osteoarthrosis in these joints.

Hand-cycling : an active form of wheeled mobility, recreation, and sports

By studying exercise and performance in hand-cycling in both activities of daily living and in Paralympic sport settings, new insights can be gained for rehabilitation practice, adapted physical activity, and sports. This review looks into the pros and cons of hand-cycling in both rehabilitation and optimal sports performance settings as suggested from the current-but still limited-scientific literature and experimentation. Despite the limited evidence-base and the diversity of study approaches and methodologies, this study suggests an important role for hand-cycling during and after rehabilitation, and in wheeled mobility recreation and sports. An approach that combines biomechanical, physiological, and psychosocial elements may lead to a better understanding of the benefits of hand-cycling and of the fundamentals of exercise in rehabilitation, activities of daily living, and sports.

The effect of crank position and backrest inclination on shoulder load and mechanical efficiency during handcycling

Handbikes come in different models and setups, but only limited knowledge is available on the handbike‐user interface. The aim of this study was to identify optimal handbike setups, assuming that in such a setup mechanical efficiency is high, while shoulder load is low. Thirteen subjects with a spinal cord injury (paraplegia) performed handcycling with different handbike setups at constant power output: four crank positions (two distances, two heights) and four backrest inclinations. The O2‐consumption, kinetics, and kinematics were measured to calculate mechanical efficiency and shoulder load (glenohumeral contact force, net shoulder moments, and rotator cuff force). The analysis showed that more upright backrest positions resulted in lower shoulder load compared with the most reclined position [glenohumeral contact force (260 vs 335 N), supraspinatus (14.4% vs 18.2%), and infraspinatus force (5.4% vs 9.8%)], while there was no difference in efficiency. Except for a reduction in subscapularis force at the distant position, no differences in shoulder load or efficiency were found between crank positions. Recreational handbike users, who want to improve their physical capacity in a shoulder‐friendly way, should set up their handbike with a more upright backrest position and a distant crank placement.

Acromioclavicular joint arthrosis in persons with spinal cord injury and able-bodied persons

Objective:To compare the prevalence, severity and risk of acromioclavicular (AC) joint arthrosis in persons presenting with shoulder pain between a spinal cord injury (SCI) and able-bodied population. In the SCI population, prevalence and severity of AC joint arthrosis were examined with respect to age, gender and lesion characteristics.Methods:Retrospective analysis of medical records and magnetic resonance images (MRI) collected in an outpatient orthopaedics clinic.Results:Sixty-eight persons with SCI and 105 able-bodied persons were included in the study. The overall MRI prevalence of AC joint arthrosis was 98% and 92%, respectively. In both groups AC joint arthrosis was frequently accompanied by MRI diagnosis of rotator cuff tears and biceps tendon ruptures. Sensitivity of clinical testing was found to be low in SCI (0.31) and in able-bodied persons (0.24). The odds of increasingly severe arthrosis were nearly four times higher in persons with SCI as compared with able-bodied persons (P<0.0001), about 72% lower in females as compared with males (P=0.0001), and 10% higher per additional year of age (P<0.0001). Arthrosis severity in the SCI-group was weakly associated with time since injury, not with neurological classification of SCI or level of injury (paraplegia vs tetraplegia).Conclusion:SCI patients presenting with shoulder pain showed similar prevalence, yet more advanced, AC joint arthrosis than able-bodied patients. As early diagnosis of arthrosis is a prerequisite for the initiation of successful conservative interventions of shoulder deterioration, we recommend routine assessment of shoulder status including diagnostic imaging during check-ups.

Submaximal arm crank ergometry: Effects of crank axis positioning on mechanical efficiency, physiological strain and perceived discomfort

Purpose: To evaluate the effect of the spatial orientation of the crank axis on mechanical efficiency, physiological strain and perceived discomfort in submaximal synchronous arm crank ergometry. Methods: Twelve able-bodied individuals performed 12 submaximal exercise bouts of 3 minutes (women: 20 W/25 W; men: 25 W/35 W). The crank axis position was defined by elbow and shoulder angle. Results: The results showed that a crank set-up with an elbow angle of 30° was more efficient than 15°; oxygen consumption and minute ventilation were significantly lower. No significant effects were seen for shoulder angle. Power output and gender showed obvious effects. Discussion and conclusion: The magnitude of this effect and the absence of any significant shoulder angle effects may be due to the relative low exertion levels that were evaluated. An elbow angle of 30° flexion in arm crank exercise is favourable compared to an elbow angle of 15° in able-bodied untrained subjects.

Propulsion effectiveness of synchronous handcycling

The purpose of this study was to evaluate the effectiveness of force application during submaximal handcycling. In a laboratory subjects propelled a kinetics-instrumented handcycle on a treadmill at 3 different speeds, while power output was kept constant at 35 W by a pulley system. Mean fraction of effective force (FEF) was between 79 and 83% and significantly influenced by the velocity. For 6 subjects a pattern of FEF was found showing an average FEF above 80% between -7 ° and 100 ° and between 205 ° and 310 ° of the crank rotation, where at 0 ° the crank is pointing towards the subject. It still has to be studied whether FEF and mechanical efficiency are related. A linked segment model analysis will be necessary to study the effect of gravity on the applied forces and joint torques.

Effect of seat height on the propulsion effectiveness and the glenohumeral joint load in handrim wheelchair propulsion

The purpose of this study was to evaluate the effectiveness of force application and the load on the glenohumeral joint during handrim wheelchair propulsion at two different seat heights. In a research laboratory able-bodied male subjects propelled a wheelchair fitted with a SmartWheel on a treadmill at 3 different speeds, while power output was kept constant at 25 W by a pulley system. There was no effect of seat height on the propulsion effectiveness and the glenohumeral joint load under the current experimental conditions.