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ABSTRACT: To study the effect of botulinum toxin A in the subscapular muscle on shoulder pain and humerus external rotation.
22 stroke patients with spastic hemiplegia, substantial shoulder pain and reduced external rotation of the humerus participated in a randomised, double blind, placebo controlled effect study. Injections of either botulinum toxin A (Botox, 2x50 units) or placebo were applied to the subscapular muscle at two locations. Pain was scored on a 100 mm vertical Visual Analogue Scale; external rotation was recorded by means of electronic goniometry. Assessments were carried out at 0 (baseline), 6 and 12 weeks.
21 patients completed the study. We observed no significant changes in pain or external rotation as a result of administration of botulinum toxin A. External rotation improved significantly (p = 0.001) for both the treatment group (20.4 degrees (16.6) to 32.1 degrees (14.0)) and the control group (10.3 degrees (19.5) to 23.7 degrees (20.7)) as a function of time.
Application of botulinum toxin A into the subscapular muscle for reduction of shoulder pain and improvement of humeral external rotation in spastic hemiplegia does not appear to be clinically efficacious.
Journal of neurology, neurosurgery, and psychiatry 06/2008; 79(5):581-3. · 4.87 Impact Factor
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ABSTRACT: Clonus is a self sustained oscillatory movement of the extremities often seen after lesions of the central nervous system. There is still controversy about the origin of clonus whether it is i) an autonomous pacemaker-like oscillator, ii) a reflexive mediated feedback property or iii) a combination of both. With the use of a haptic robot we were able to initiate clonus in patients (n=7). We would conclude the underlying mechanism to be autonomous when the frequency of movement would not change with additional external damping and inertia. Results however showed distinct changes in frequency of movement, varying the peripheral conditions. Furthermore, when the clonus was suddenly stopped by a controlled increase of a huge external damper, clear bursting was observed in the triceps EMG while there was no rotation of the ankle. In conclusion, i) clonus is initiated by spinal reflexes (probably la or lb afferents), ii) also during clonus the same spinal reflexes are likely to contribute to the maintenance of ankle rotation and iii) the after bursting directs to self sustained firing of neural circuitry. These conclusions implicate the existence of a reflexive controlled oscillator. Future research will be performed using detailed model simulations to test different gains between reflexive feedback and neural oscillations, e.g. from the alpha - motorneurons.
Rehabilitation Robotics, 2007. ICORR 2007. IEEE 10th International Conference on; 07/2007
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ABSTRACT: A mechanical deficit due to a massive rotator cuff tear is generally concurrent to a pain-induced decrease of maximum arm elevation and peak elevation torque. The purpose of this study was to measure shoulder muscle coordination in patients with massive cuff tears, including the effect of subacromial pain suppression. Ten patients, with MRI-proven cuff tears, performed an isometric force task in which they were asked to exert a force in 24 equidistant intervals in a plane perpendicular to the humerus. By means of bi-polar surface electromyography (EMG) the direction of the maximal muscle activation or principal action of six muscles, as well as the external force, were identified prior to, and after subacromial pain suppression. Subacromial lidocaine injection led to a significant reduction of pain and a significant increase in exerted arm force. Prior to the pain suppression, we observed an activation pattern of the arm adductors (pectoralis major pars clavicularis and/or latissimus dorsi and/or teres major) during abduction force delivery in eight patients. In these eight patients, adductor activation was different from the normal adductor activation pattern. Five out of these eight restored this aberrant activity (partly) in one or more adductor muscles after subacromial lidocaine injection. Absence of glenoid directed forces of the supraspinate muscle and compensation for the lost supraspinate abduction torque by the deltoideus leads to destabilizating forces in the glenohumeral joint, with subsequent upward translation of the humeral head and pain. In order to reduce the superior translation force, arm adductors will be co-activated at the cost of arm force and abduction torque. Pain seems to be the key factor in this (avoidance) mechanism, explaining the observed limitations in arm force and limitations in maximum arm elevation in patients suffering subacromial pathologies. Masking this pain may further deteriorate the subacromial tissues as a result of proximal migration of the humeral head and subsequent impingement of subacromial tissues.
Manual Therapy 09/2006; 11(3):231-7. · 1.88 Impact Factor
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ABSTRACT: Massive rotator cuff tears impose restraints on overhand arm functionality and are often accompanied by pain. After musculotendinous Teres Major transfer, overhand arm function is generally restored and pain is reduced. The assumed mechanical abduction insufficiency and Teres Major muscle function adaptation will be experimentally verified.
Principal Teres Major muscle activation (surface IEMG averaged over 3s) is recorded for 12-24 isometric and isotonic force directions perpendicular to the 60 degrees forward flexed humerus in three conditions: prior to surgery (n = 6 patients), prior to surgery and after subacromial anaesthetic (n = 6) and post-surgery (n = 3). Principal direction and on-, offset directions were estimated.
Teres Major activation adapts both to pathological and post surgery conditions: the normal activation during adduction changes into activation during forward flexion or abduction. Glenohumeral stabilisation, not abduction torque, seems to be the explanation for post surgery Teres Major transfer success.
The pathological absence of Supraspinatus and Infraspinatus forces during forward flexion result in increased upward glenohumeral instability. The superior translations are compensated for by Teres Major activity during forward flexion. This translation-'force' function conflicts with the adduction-generating rotation-'torque' function. This may explain the pain-induced reduction of arm elevation in these patients. Musculotendinous transfer solves the force-torque conflict by changing the moment arm of the Teres Major from adduction to abduction. Teres Major can now both compensate for the loss of Supraspinatus and Infraspinatus forces needed for glenohumeral stabilisation and contribute to forward flexion of the arm.
Clinical Biomechanics 02/2006; 21 Suppl 1:S27-32. · 2.07 Impact Factor
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ABSTRACT: To compare three dimensional movement patterns of the affected and non-affected shoulder in patients with a frozen shoulder before and after physical therapy.
Patients with a unilateral frozen shoulder were assessed before and after three months of treatment. Three dimensional movement analysis was performed with the "Flock of Birds" electromagnetic tracking device while the patient raised their arms in three directions. Slopes of the regression lines of glenohumeral joint rotation versus scapular rotation, reflecting the scapulohumeral rhythm, were calculated. All assessments were made for both the affected and the unaffected side. Additional assessments included conventional range of motion (ROM) measurements and visual analogue scales (VAS) (0-100 mm) for shoulder pain at rest, during movement, and at night.
Ten patients with a unilateral frozen shoulder were included. The slopes of the curves of the forward flexion, scapular abduction, and abduction in the frontal plane of the affected and the unaffected side were significantly different in all three movement directions. Mean differences were 0.267, 0.215, and 0.464 (all p values <0.005), respectively. Mean changes of the slopes of the affected side after treatment were 0.063 (p=0.202), 0.048 (p=0.169), and 0.264 (p=0.008) in forward flexion, scapular abduction, and abduction in the frontal plane, respectively. All patients showed significant improvement in active ROM (all p<0.005), and the VAS for pain during movement and pain at night (p<0.05).
With a three dimensional electromagnetic tracking system the abnormal movement pattern of a frozen shoulder, characterised by the relatively early laterorotation of the scapula in relation to glenohumeral rotation during shoulder elevation, can be described and quantified. Moreover, the system is sufficiently sensitive to detect clinical improvements. Its value in other shoulder disorders remains to be established.
Annals of the Rheumatic Diseases 02/2002; 61(2):115-20. · 8.73 Impact Factor
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ABSTRACT: OBJECTIVE: To describe a recording and processing methodology for obtaining kinematic data of the shoulder which meets three more criteria besides usual requirements regarding precision and accuracy: sufficient speed, obtaining complete 3D kinematics including joint rotations, and usage of coordinate systems based on reference points. DESIGN: Static recordings of shoulder bone orientations during standardized humerus elevations based on the palpation technique using a six-degree-of-freedom electromagnetic tracking device. BACKGROUND: An easy, fast, well standardized measurement methodology for obtaining complete 3D shoulder kinematic data is urgently needed for fundamental musculoskeletal and clinical research. METHODS: A measurement methodology was designed and developed. Shoulder kinematics were obtained from repeated measurements on 15 healthy subjects performed by two observers. Inter-trial, inter-day, inter-observer and inter-subject variability were established. Results were compared to literature. RESULTS: Complete kinematic descriptions were obtained. A measurement speed of about one position per second could be reached. The measured kinematics and accuracy of the measurements were found to be in concordance with the literature. CONCLUSION: All previously formulated criteria for a clinical useful method for obtaining shoulder kinematics have been met.
Clinical biomechanics (Bristol, Avon) 07/1998; 13(4-5):280-292. · 1.76 Impact Factor
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ABSTRACT: Instead of hyper-reflexia as sole paradigm, post-stroke movement disorders are currently considered the result of a complex interplay between neuronal and muscular properties, modified by level of activity. We used a closed loop system identification technique to quantify individual contributors to wrist joint stiffness during an active posture task. Continuous random torque perturbations applied to the wrist joint by a haptic manipulator had to be resisted maximally. Reflex provoking conditions were applied i.e. additional viscous loads and reduced perturbation signal bandwidth. Linear system identification and neuromuscular modeling were used to separate joint stiffness into the intrinsic resistance of the muscles including co-contraction and the reflex mediated contribution. Compared to an age and sex matched control group, patients showed an overall 50% drop in intrinsic elasticity while their reflexive contribution did not respond to provoking conditions. Patients showed an increased mechanical stability compared to control subjects. Post stroke, we found active posture tasking to be dominated by: 1) muscle weakness and 2) lack of reflex adaptation. This adds to existing doubts on reflex blocking therapy as the sole paradigm to improve active task performance and draws attention to muscle strength and power recovery and the role of the inability to modulate reflexes in post stroke movement disorders.
Journal of NeuroEngineering and Rehabilitation 2009, 6.
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ABSTRACT: Main claims of the literature are that functional recovery of the paretic upper limb is mainly defined within the first month post stroke and that rehabilitation services should preferably be applied intensively and in a task-oriented way within this particular time window. EXplaining PLastICITy after stroke (acronym EXPLICIT-stroke) aims to explore the underlying mechanisms of post stroke upper limb recovery. Two randomized single blinded trials form the core of the programme, investigating the effects of early modified Constraint-Induced Movement Therapy (modified CIMT) and EMG-triggered Neuro-Muscular Stimulation (EMG-NMS) in patients with respectively a favourable or poor probability for recovery of dexterity.
BMC Neurology 2008, 8:49doi:10.1186/1471-2377-8-49.
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ABSTRACT: Background Instead of hyper-reflexia as sole paradigm, post-stroke movement disorders are currently considered the result of a complex interplay between neuronal and muscular properties, modified by level of activity. We used a closed loop system identification technique to quantify individual contributors to wrist joint stiffness during an active posture task. Methods Continuous random torque perturbations applied to the wrist joint by a haptic manipulator had to be resisted maximally. Reflex provoking conditions were applied i.e. additional viscous loads and reduced perturbation signal bandwidth. Linear system identification and neuromuscular modeling were used to separate joint stiffness into the intrinsic resistance of the muscles including co-contraction and the reflex mediated contribution. Results Compared to an age and sex matched control group, patients showed an overall 50% drop in intrinsic elasticity while their reflexive contribution did not respond to provoking conditions. Patients showed an increased mechanical stability compared to control subjects.
Journal of NeuroEngineering and Rehabilition, 6 (29), 2009.
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BMC Neurology, 8 (49).
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ABSTRACT: Objective. To present a method to determine the position and orientation of the mean optimal flexion axis of the elbow in vivo to be used in clinical research.Design. Registering the movements of the forearm with respect to the upper arm during five cycles of flexion and extension of the elbow using a 6 degrees-of-freedom electromagnetic tracking device.Background. Loosening of elbow endoprostheses could be caused by not placing the prostheses in a biomechanically optimal way. To evaluate the placement of endoprostheses with regard to loosening, a method to determine the elbow axis is needed.Methods. The movements of the right forearm with respect to the upper arm during flexion and extension were registered with a 6 degrees-of-freedom electromagnetic tracking device. A mean optimal instantaneous helical axis of 10 elbows was calculated in a coordinate System related to the humerus.Results. The average position of the flexion/extension axis was 0.81cm (SD 0.66 cm) cranially and 1.86 cm (SD 0.72 cm) ventrally of the epicondylus lateralis. The average angle with the frontal plane was 15.3 ° (SD 2 °).Conclusions. A useful estimation of the position and orientation of a mean optimal flexion axis can be obtained in vivo.
Clinical Biomechanics.
