Garth Johnson

A review of the properties and limitations of the Ashworth and modified Ashworth Scales as measures of spasticity

Background: The Ashworth Scale and the modified Ashworth Scale are the primary clinical measures of spasticity. A prerequisite for using any scale is a knowledge of its characteristics and limitations, as these will play a part in analysing and interpreting the data. Despite the current emphasis on treating spasticity, clinicians rarely measure it. Objectives: To determine the validity and the reliability of the Ashworth and modified Ashworth Scales. Study design: A theoretical analysis following a structured literature review (key words: Ashworth; Spasticity; Measurement) of 40 papers selected from the BIDS-EMBASE, First Search and Medline databases. Conclusions: The application of both scales would suggest that confusion exists on their characteristics and limitations as measures of spasticity. Resistance to passive movement is a complex measure that will be influenced by many factors, only one of which could be spasticity. The Ashworth Scale (AS) can be used as an ordinal level measure of resistance to passive movement, but not spasticity. The modified Ashworth Scale (MAS) will need to be treated as a nominal level measure of resistance to passive movement until the ambiguity between the ‘1’ and ‘1+’ grades is resolved. The reliability of the scales is better in the upper limb. The AS may be more reliable than the MAS. There is a need to standardize methods to apply these scales in clinical practice and research.

Reliability and validity of arm function assessment with standardized guidelines for the Fugl-Meyer Test, Action Research Arm Test and Box and Block Test: a multicentre study

Objectives: To establish: (1) inter-rater and test–retest reliability of standardized guidelines for the Fugl-Meyer upper limb section, Action Research Arm Test and Box and Block Test in patients with paresis secondary to stroke, multiple sclerosis or traumatic brain injury and (2) correlation between these arm motor scales and more general measures of impairment and activity limitation. Design: Multicentre cohort study. Setting: Three European referral centres for neurorehabilitation. Subjects: Thirty-seven stroke, 14 multiple sclerosis and five traumatic brain injury patients. Main measures: Scores of the Fugl-Meyer Test (arm section), Action Research Arm Test, and Box and Block Test derived from video information. Results: All three motor tests showed very high inter-rater and test–retest reliability (ICC and rho for main variables>0.95). Correlation between the motor scales was very high (rho>0.92). Motor scales correlated moderately highly with the Hemispheric Stroke Scale, a measure of impairment (rho=0.660–0.689), but not with the Modified Barthel Index, a measure of the ability to cope with basic activities of daily living (rho=0.044–0.086). Conclusions: The standardized guidelines assured comparability of test administration and scoring across clinical facilities. The arm motor scales provided information that was not identical to information from the Hemispheric Stroke Scale or the Modified Barthel Index. Address for correspondence: Priv.-Doz. Dr T Platz, Klinik Berlin, Kladower Damm 223, 14089 Berlin, Germany.

Spasticity: Clinical perceptions, neurological realities and meaningful measurement

The aim of this paper is to review briefly our understanding of the phenomenon of spasticity based in current evidence.

Anatomy and actions of the trapezius muscle

Dissection studies revealed the fascicular anatomy of the trapezius. Its occipital and nuchal fibres passed downwards but mainly transversely to insert into the clavicle. Fibres from C7 and T1 passed transversely to reach the acromion and spine of the scapula. Its thoracic fibres converged to the deltoid tubercle of the scapula. Volumetric studies demonstrated that the fibres from C7, T1, and the lower half of ligamentum nuchae were the largest. The essentially transverse orientation of the upper and middle fibres of trapezius precludes any action as elevators of the scapula as commonly depicted. Rather the action of these fibres is to draw the scapula and clavicle backwards or to raise the scapula by rotating the clavicle about the sternoclavicular joint. By balancing moments the trapezius relieves the cervical spine of compression loads.

A systematic review of the Tardieu Scale for the measurement of spasticity

Background. The Tardieu Scale has been suggested a more appropriate clinical measure of spasticity than the Ashworth or modified Ashworth Scales. It appears to adhere more closely to Lances definition of spasticity as it involves assessment of resistance to passive movement at both slow and fast speeds. Objective. To review the available literature in which the Tardieu Scale has been used or discussed as a measure of spasticity, with a view to determining its validity and reliability. Study design. A systematic review of all literature found related to the Tardieu Scale (keywords: Tardieu scale, spasticity) from Pubmed and Ovid databases, including medline, CINAHL, EMBASE, Journals at Ovid full text, EBM reviews and Cochrane database of systematic reviews. Hand searching was also used to track the source literature. Conclusions. In theory, we can acknowledge that the Tardieu Scale does, in fact, adhere more closely to Lances definition of spasticity. However, there is a dearth of literature investigating validity and reliability of the scale. Some studies have identified the Tardieu Scale to be more sensitive than other measures, to change following treatment with botulinum toxin. Further studies need to be undertaken to clarify the validity and reliability of the scale for a variety of muscle groups in adult neurological patients.

A method for the measurement of three-dimensional scapular movement

Many disorders of the shoulder complex are accompanied by changes in the pattern of scapular motion which is difficult to measure except radiographically. In order to study the three-dimensional motion of the scapula which accompanies arm movements, a technique has been developed using a three-pointed locater which can be applied over three bony landmarks - the acromial angle, the inferior angle, and the root of the scapular spine. The spatial orientation of the locater relative to the trunk was measured using an electromagnetic movement sensor (isotrak) which has been shown to be clinically reliable. Measurements of scapular plane rotations during abduction showed particularly good agreement with published data; variations in measurements of the out-of-plane angles were attributed to difficulties of contacting the acromion reliably when the deltoid muscle was contracted. It is concluded that the system is suitable for clinical use in the study of shoulder pathology.

A biomechanical investigation into the validity of the modified Ashworth Scale as a measure of elbow spasticity

Objective: To investigate the criterion validity of the modified Ashworth Scale. Population: Volunteers from a stroke population admitted to a district general hospital stroke unit diagnosed with a first ever stroke less than 26 weeks previously. Outcome measures: Resistance to passive movement about the elbow was simultaneously quantified (biomechanically) and graded (modified Ashworth Scale). Passive range of movement and peak instantaneous velocity during passive movement were also measured. Analysis: Criterion validity was investigated as convergent construct validity (using the Spearmans correlation coefficient) and concurrent validity (using analysis of variance). Results: One hundred measurements were taken on 63 subjects. Correlation between the modified Ashworth Scale and resistance to passive movement was 0.511. Resistance to passive movement and velocity showed significant differences between the modified Ashworth score of ‘0’ and a modified Ashworth score greater than ‘0’ (p < 0.01). There were no significant differences between MAS ‘1’, ‘1+’ and ‘2’. Resistance to passive movement in the impaired arm was significantly higher than in the nonimpaired arm (p < 0.01). Conclusion: The modified Ashworth Scale does not provide a valid measure of spasticity at lower grades but it may provide a measure of resistance to passive movement.

The measurement of three dimensional scapulohumeral kinematics – a study of reliability

OBJECTIVE To validate a system, using electromagnetic movement sensors, for the simultaneous measurement of scapular and humeral positions. DESIGN The study was designed to analyse the repeatability and to quantify the inherent measurement errors, using two observers to measure the movements of five normal subjects. BACKGROUND Following an earlier study of a system to measure three dimensional scapula motion, the method has been developed to incorporate simultaneous measurement of humeral and scapular position using a new design of scapula locator and a two-channel measurement system. METHODS The system was used to measure the scapula movements accompanying abduction of the shoulder. The scapula locator was applied at 10 degrees intervals of abduction. This was measured initially using a fluid filled goniometer, but, in a second part of the study, using an additional motion sensor. RESULTS In the single channel study, the 95% confidence intervals were less than 4 degrees and 10 mm. When simultaneous measurement of arm position was performed the confidence intervals were little changed. CONCLUSIONS A new system for the measurement of scapulohumeral relationships has been shown to have good inter-and intraobserver reliability. This study opens the way for a full investigation of the scapula motion accompanying three dimensional shoulder motion in both normal subjects and in patients having shoulder pathology.

Multivariate analysis of the Fugl-Meyer outcome measures assessing the effectiveness of GENTLE/S robot-mediated stroke therapy

BackgroundRobot-mediated therapies offer entirely new approaches to neurorehabilitation. In this paper we present the results obtained from trialling the GENTLE/S neurorehabilitation system assessed using the upper limb section of the Fugl-Meyer (FM) outcome measure.MethodsWe demonstrate the design of our clinical trial and its results analysed using a novel statistical approach based on a multivariate analytical model. This paper provides the rational for using multivariate models in robot-mediated clinical trials and draws conclusions from the clinical data gathered during the GENTLE/S study.ResultsThe FM outcome measures recorded during the baseline (8 sessions), robot-mediated therapy (9 sessions) and sling-suspension (9 sessions) was analysed using a multiple regression model. The results indicate positive but modest recovery trends favouring both interventions used in GENTLE/S clinical trial. The modest recovery shown occurred at a time late after stroke when changes are not clinically anticipated.ConclusionThis study has applied a new method for analysing clinical data obtained from rehabilitation robotics studies. While the data obtained during the clinical trial is of multivariate nature, having multipoint and progressive nature, the multiple regression model used showed great potential for drawing conclusions from this study.An important conclusion to draw from this paper is that this study has shown that the intervention and control phase both caused changes over a period of 9 sessions in comparison to the baseline. This might indicate that use of new challenging and motivational therapies can influence the outcome of therapies at a point when clinical changes are not expected.Further work is required to investigate the effects arising from early intervention, longer exposure and intensity of the therapies. Finally, more function-oriented robot-mediated therapies or sling-suspension therapies are needed to clarify the effects resulting from each intervention for stroke recovery.

The morphology and biomechanics of latissimus dorsi

OBJECTIVE: To determine the morphology of the latissimus dorsi in order to assess its actions on the shoulder, the lumbar spine and the sacroiliac joint. DESIGN: A dissection study accompanied by an analysis of the force vectors of the muscle and its parts. BACKGROUND: Although recognised as a muscle of the shoulder, latissimus dorsi has been accorded a role as an extensor of the lumbar spine, and is said to brace the sacroiliac joint. Consideration of the anatomy of the latissimus dorsi suggests that the magnitude of these actions has been overstated. METHODS: The fascicular anatomy of the latissimus dorsi was determined by dissection in five adult cadavers. The size, attachments, and orientation of each fascicle were determined. By applying a force coefficient the maximum force of each fascicle was estimated from its physiological cross-sectional area. By summing the forces and moments of each fascicle the maximum force exerted by latissimus dorsi was calculated for its actions on the shoulder, the lumbar spine, and the sacroiliac joint. RESULTS: The latissimus dorsi was found to consist of a series of fascicles with segmental attachments to the lower six thoracic spinous processes, the L1 and L2 spinous processes, the lateral raphe of the thoracolumbar fascia, the iliac crest and the lower three ribs. These fascicles were uniform in size across a given muscle but varied from specimen to specimen. The maximum total force exerted by the latissimus dorsi on the shoulder was estimated to range between 162 and 529 N, but in view of the attachments of the muscle, only a portion of that force can be exerted on the lumbar spine. The maximum extensor moment exerted on the lumbar spine was calculated to be 6.3 N m. The maximum force exerted across the sacroiliac joint was calculated to be 30 N. CONCLUSIONS: The latissimus dorsi is designed to move the upper limb or to raise the entire trunk in brachiation. Its possible contribution to extension of the lumbar spine is trivial as is its capacity to brace the sacroiliac joint. RELEVANCE: Despite assertions and concerns to the contrary, the latissimus dorsi is of little mechanical importance in the lumbosacral region.