Post-Polio Syndrome

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The data collection and analysis of this research study was largely the work of Frans Nollet and Anita Beelen. Other senior authors provided input at various stages of planning and writing. Professor Anthony J Sargeant was the supervisor for the PhD thesis of which this work formed a part.

Disability and functional assessment in former polio patients with and without postpolio syndrome

Frans Nollet, Anita Beelen, Prins MH, Marianne de Visser, Anthony J Sargeant, Lankhorst GJ, de Jong BA 

Archives of Physical Medicine and Rehabilitation

Arch Phys Med Rehabil. 1999 Feb;80(2):136-143
Abstract
OBJECTIVES: To compare perceived health problems and disability in former polio subjects with postpolio syndrome (PPS) and those without postpolio syndrome (non-PPS), and to evaluate perceived health problems, disability, physical performance, and muscle strength.
DESIGN: Cross-sectional survey; partially blinded data collection.
SUBJECTS: One hundred three former polio subjects, aged 32 to 60yrs. This volunteer sample came from referrals and patient contacts. Criterion for PPS: new muscle weakness among symptoms.
MAIN OUTCOME MEASURES: Nottingham Health Profile (NHP), adapted D-code of the International Classification of Impairments, Disabilities and Handicaps, performance test, and muscle strength assessment.
RESULTS: PPS subjects (n = 76) showed higher scores (p < .001) than non-PPS subjects (n = 27) within the NHP categories of physical mobility, energy, and pain. On a 16-item Polio Problems List, 78% of PPS subjects selected fatigue as their major problem, followed by walking outdoors (46%) and climbing stairs (41%). The disabilities of PPS subjects were mainly seen in physical and social functioning. No differences in manually tested strength were found between patient groups. PPS subjects needed significantly more time for the performance test than non-PPS subjects and their perceived exertion was higher. Perceived health problems (NHP-PhysMobility) correlated significantly with physical disability (r = .66), performance-time (r = .54), and muscle strength (r = .38). With linear regression analysis, 54% of the NHP-PhysMobility score could be explained by the performance test (time and exertion), presence of PPS, and muscle strength, whereas strength itself explained only 14% of the NHP-PhysMobility score.
CONCLUSIONS: PPS subjects are more prone to fatigue and have more physical mobility problems than non-PPS subjects. In former polio patients, measurements of perceived health problems and performance tests are the most appropriate instruments for functional evaluation
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In vivo measurements of the triceps surae complex architecture in man: implications for muscle function

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Costis Maganaris was a brilliant PhD student (now Professor) supervised by Vasilios Baltzopoulos and Professor Anthony J Sargeant. This important study published in Journal of Physiology investigated how changes in muscle architecture during muscle contraction of human triceps surae muscle complex can distort calculations of mechanical output.

In vivo measurements of the triceps surae complex architecture in man: implications for muscle function

Constantinos N Maganaris, Vasilios Baltzopoulos, Anthony J Sargeant.

Journal of Physiology
J Physiol. 1998 Oct 15;512 ( Pt 2):603-14
1. The objectives of this study were to (1) quantify experimentally in vivo changes in pennation angle, fibre length and muscle thickness in the triceps surae complex in man in response to changes in ankle position and isometric plantarflexion moment and (2) compare changes in the above muscle architectural characteristics occurring in the transition from rest to a given isometric plantarflexion intensity with the estimations of a planimetric muscle model assuming constant thickness and straight muscle fibres.
2. The gastrocnemius medialis (GM), gastrocnemius lateralis (GL) and soleus (SOL) muscles of six males were scanned with ultrasonography at different sites along and across the muscle belly at rest and during maximum voluntary contraction (MVC) trials at ankle angles of -15 deg (dorsiflexed direction), 0 deg (neutral position), +15 deg (plantarflexed direction) and +30 deg. Additional images were taken at 80, 60, 40 and 20% of MVC at an ankle angle of 0 deg.
3. In all three muscles and all scanned sites, as ankle angle increased from -15 to +30 deg, pennation increased (by 6-12 deg, 39-67%, P < 0.01 at rest and 9-16 deg, 29-43%, P < 0.01 during MVC) and fibre length decreased (by 15-28 mm, 32-34%, P < 0.01 at rest and 8-10 mm, 27-30%, P < 0.05 during MVC). Thickness in GL and SOL increased during MVC compared with rest (by 5-7 mm, 36-47%, P < 0.01 in GL and 6-7 mm, 38-47%, P < 0.01 in SOL) while thickness of GM did not differ (P > 0.05) between rest and MVC.
4. At any given ankle angle the model underestimated changes in GL and SOL occurring in the transition from rest to MVC in pennation angle (by 9-12 deg, 24-38%, P < 0.01 in GL and 9-14 deg, 25-28%, P < 0.01 in SOL) and fibre length (by 6-15 mm, 22-39%, P < 0.01 in GL and 6-8 mm, 23-24%, P < 0.01 in SOL).
5. The findings of the study indicate that the mechanical output of muscle as estimated by the model used may be unrealistic due to errors in estimating the changes in muscle architecture during contraction compared with rest

Research into human tendon properties by Costis Maganaris, Vassilios Baltzopolous and Anthony J Sargeant

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Changes in Achilles tendon moment arm from rest to maximum isometric plantarflexion: In vivo observations in man

Article (PDF Available)inThe Journal of Physiology 510 ( Pt 3)(3):977-85 · August 1998with85 Reads

DOI: 10.1111/j.1469-7793.1998.977bj.x · Source: PubMed
  • 35.76 · Liverpool John Moores University
  • 38.82 · Liverpool John Moores University
  • 41.33 · VU University Amsterdam
    Abstract
    1. The purpose of the present study was to examine the effect of a plantarflexor maximum voluntary contraction (MVC) on Achilles tendon moment arm length.
    2. Sagittal magnetic resonance (MR) images of the right ankle were taken in six subjects both at rest and during a plantarflexor MVC in the supine position at a knee angle of 90 deg and at ankle angles of -30 deg (dorsiflexed direction), -15 deg, 0 deg (neutral ankle position), +15 deg (plantarflexed direction), +30 deg and +45 deg. A system of mechanical stops, support triangles and velcro straps was used to secure the subject in the above positions. Location of a moving centre of rotation was calculated for ankle rotations from -30 to 0 deg, -15 to +15 deg, 0 to +30 deg and +15 to +45 deg. All instant centres of rotation were calculated both at rest and during MVC. Achilles tendon moment arms were measured at ankle angles of -15, 0, +15 and +30 deg.
    3. At any given ankle angle, Achilles tendon moment arm length during MVC increased by 1-1.5 cm (22-27 %, P < 0.01) compared with rest. This was attributed to a displacement of both Achilles tendon by 0.6-1.1 cm (P < 0.01) and all instant centres of rotation by about 0.3 cm (P < 0.05) away from their corresponding resting positions.
    4. The findings of this study have important implications for estimating loads in the musculoskeletal system. Substantially unrealistic Achilles tendon forces and moments generated around the ankle joint during a plantarflexor MVC would be calculated using resting Achilles tendon moment arm measurements.

    Changes in Achilles tendon moment arm from rest to maximum isometric plantarflexion: In vivo observations in man (PDF Download Available). Available from: https://www.researchgate.net/publication/13623782_Changes_in_Achilles_tendon_moment_arm_from_rest_to_maximum_isometric_plantarflexion_In_vivo_observations_in_man [accessed May 1, 2017].

Functional and structural changes after disuse of human muscle – first study to quantify disuse muscle atrophy at fibre level in humans

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Clinical Science and Molecular Medicine (1977) 52, 337-342. Functional and structural changes after disuse of human muscle – Authors: ANTHONY J SARGEANT,* C. T. M. DAVIES,* R. H. T. EDWARDS, C. MAUNDER AND A. YOUNG *Medical Research Council Environmental Physiology Unit, London School of Hygiene and Tropical Medicine, University of London, and Jerry Lewis Muscle Research Centre, Royal Postgraduate Medical School, Hammersmith Hospital, London

Summary

1. Seven patients who had suffered unilateral leg fracture were studied after removal of immobilizing plaster casts.

2. Leg volume measured anthropometrically was reduced by 12% in the injured leg (5.68 f 1.05 litres) compared with the uninjured (6.43 f 0.87 litres). Associated with this loss was a similar reduction in the net maximum oxygen uptake achieved in one-leg cycling, from 1.89 k 0.21 l/min in the uninjured leg to 1.57+0.18 l/min in the injured.

3. Measured by a percutaneous needle biopsy technique, a reduction of 42% was found in the cross-sectional area of the muscle fibres sampled from the vastus lateralis of the injured compared with the uninjured leg.

4. Staining for myosin adenosine triphosphatase activity showed that both type I and I1 fibres were affected, being reduced respectively from 3410 to 1840 pm2 and from 3810 to 2390 pm2 cross-sectional area.

5. Possible reasons and implications are discussed for the discrepancy between the magnitude of the difference observed in the gross measurement of leg function (maximum oxygen uptake) and structure (leg volume) as compared with the cellular level (cross-sectional fibre area).

 

Correspondence: Dr A. J. Sargeant, MRC Environmental Physiology Unit, London School of Hygiene and Tropical Medicine, University of London, Keppel Street (Gower Street), London WClE 7HT.

Introduction

Atrophy of the affected limb and loss of muscle power follows bone fracture and subsequent immobilization. Years of experience have enabled the rehabilitation professions to develop empirical programmes to reverse these changes. However, the efficacy of such programmes may be further improved if we can increase our understanding of the atrophic response to disuse in human muscle. Recent studies showed that 15 weeks immobilization in a long-leg plaster cast after fracture reduced the fat-free volume of the affected leg by 12%, which was accompanied by a similar fall in the maximum oxygen uptake ( ~oz,,,,=.) achieved with oneleg pedalling (Davies & Sargeant, 1975a,b). However, it was not known how far these changes in gross structure and function were reflected at a cellular level within the affected muscles. Since the work of pedalling is performed mainly by the leg extensors (A. J. Sargeant & C. T. M. Davies, unpublished work) needle biopsy was used (Edwards, Maunder, Lewis & Pearse, 1973) to study fibre atrophy in the quadriceps femoris muscle and to compare this with measurements of the gross leg volume and maximal oxygen uptake of patients recovering from unilateral leg fracture.

http://www.clinsci.org/content/ppclinsci/52/4/337.full.pdf

Structural and functional determinants of human muscle power – Review by Anthony J Sargeant

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Experimental PhysiologyExperimental Physiology

Abstract

Measurements of human power need to be interpreted in relation to the movement frequency, since that will determine the velocity of contraction of the active muscle and hence the power available according to the power–velocity relationship. Techniques are described which enable movement frequency to be kept constant during human exercise under different conditions. Combined with microdissection and analysis of muscle fibre fragments from needle biopsies obtained pre- and postexercise we have been able ‘to take the muscle apart’, having measured the power output, including the effect of fatigue, under conditions of constant movement frequency. We have shown that fatigue may be the consequence of a metabolic challenge to a relatively small population of fast fatigue-sensitive fibres, as indicated by [ATP] depletion to ∼30% of resting values in those fibres expressing myosin heavy chain isoform IIX after just 10 s of maximal dynamic exercise. Since these same fibres will have a high maximal velocity of contraction, they also make a disproportionate contribution to power output in relation to their number, especially at faster movement rates. The microdissection technique can also be used to measure phosphocreatine concentration ([PCr]), which is an exquisitely sensitive indicator of muscle fibre activity; thus, in just seven brief maximal contractions [PCr] is depleted to levels < 50% of rest in all muscle fibre types. The technique has been applied to study exercise at different intensities, and to compare recruitment in lengthening, shortening and isometric contractions, thus yielding new information on patterns of recruitment, energy turnover and efficiency.

The Physiology and Pathophysiology of Exercise Tolerance edited by Jürgen M. Steinacker, Susan A. Ward

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The Physiology and Pathophysiology of Exercise Tolerance

Jürgen M. Steinacker, ‎Susan A. Ward – 2012 – ‎Medical

Bauer, J., A.C.H.J. Rademaker, J.A. Zoladz, and A.J. Sargeant. Is reduced mechanical efficiency at high pedalling rate due to less optimally directed leg forces

 

https://books.google.co.uk/books?id=bLbeBwAAQBAJ&pg=PA251&lpg=PA251&dq=aj+sargeant&source=bl&ots=4jgoyKK-FN&sig=WCdsa7zr-2npWXKCXQrydu6gSZA&hl=en&sa=X&ved=0ahUKEwj46PT9pMnTAhXIDMAKHXUzCTkQ6AEIVjAJ#v=onepage&q=aj%20sargeant&f=false