Showing papers by "Manchester Metropolitan University published in 1998"

Visual Search Strategy, Selective Attention, and Expertise in Soccer

Abstract: This research examined the relationship between visual search strategy, selective attention, and expertise in soccer. Experienced (h = 12) and less experienced (n = 12) soccer players moved in response to filmed offensive sequences. Experiment 1 examined differences in search strategy between the two groups, using an eye movement registration system. Experienced players demonstrated superior anticipation in 3-on-3 and 1-on-l soccer simulations. There were no differences in search strategy in 3-on-3 situations. In 1-on-1 simulations, the experienced players had a higher search rate, involving more fixations of shorter duration, and fixated for longer on the hip region, indicating that this area was important in anticipating an opponent's movements. Experiment 2 examined the relationship between visual fixation and selective attention, using a spatial occlusion approach. In 3-on-3 situations, masking information “pick up” from areas other than the ball or ball passer had a more detrimental effect o...

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

Abstract: 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 0.05) 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.

The New Public Management And A New Accountability

Abstract: There has long been a disparity between the practice and the neo-Diceyan doctrine of accountability in British central government. This article shows that the New Public Management (NPM), while not itself the root cause of such disparity, has nevertheless both exacerbated and further exposed existing fault-lines. This much is evident from an examination of NPM’s theoretical bearings and from brief case studies of the Child Protection Agency and the Prison Service. Reflecting broad and deep-seated forces, the NPM is unlikely to disappear. Thus although there are certain attractions in retaining neo-Diceyan assumptions, it may be more appropriate to reconstruct the formal doctrine. Drawing upon Spiro’s notion of ‘multicentric’ accountability and within the context of calls for wider constitutional reform, the article sketches the basis for a new doctrine, having regard to relevant moralities and practicalities.

Examining and Extending Research in Coach Development

Abstract: Research to date provides two approaches to assessing coaching expertise. The first is behavioral assessment and the second is to assess coaches' knowledge base. However, we contend that both approaches are flawed due to their inability to adequately improve coach development by failing to answer three fundamental questions: What knowledge should be taught to novice coaches? What is the optimal method for teaching this knowledge? And how should we assess to encourage learning? Cognitive psychology has demonstrated that someone with expert cognitive skill is characterized as having expert declarative and procedural knowledge. Experts are further characterized by having greater organization of this knowledge. Thus the expert is able to apply expert knowledge in a more expert manner to solve complex problems in a specific domain. Properly exploiting ideas such as these can help direct future research to provide answers to the questions posed above.

Evaluating information technology in health care: barriers and challenges

Abstract: There is strong push for clinical leadership in the development and procurement of information technology in health care.1 The lack of clinical input to date has been cited as a major factor in the failure of information technology in health services2 and has prompted many clinicians to become involved in such endeavours. Furthermore, there are various clinical decision support systems available, the merits of which clinicians are expected to judge (such as Prodigy3 and Capsule4). It is essential that clinicians have a knowledge of evaluation issues in order that they can assess the strengths and weaknesses of evaluation studies and thus interpret their results meaningfully, and also contribute to the design and implementation of such studies to provide them with useful information. #### Summary points Clinicians are becoming increasingly involved in the development and procurement of information technology in health care, yet evaluation studies have provided little useful information to assist them Evaluations by means of randomised controlled trials have not yet provided any major indication of improved patient outcomes or cost effectiveness, are difficult to generalise, and do not provide the scope or detail necessary to inform decision making Clinical information systems are a different kind of intervention from drugs, and techniques used to evaluate drugs (particularly randomised controlled trials) are not always appropriate The challenge for clinical informatics is to develop multi-perspective evaluations that integrate quantitative and qualitative methods Evaluation is not just for accountability but to improve our understanding of the role of information technology in health care and our ability to deliver systems that offer a wide range of clinical and economic benefits Decision makers may be …

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

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.

The C-value/NC-value Method of Automatic Recognition for Multi-Word Terms

Abstract: Technical terms (henceforth called simply terms), are important elements for digital libraries. In this paper we present a domain-independent method for the automatic extraction of multi-word terms, from machine-readable special language corpora. The method, (C-value/NC-value), combines linguistic and statistical information. The first part, C-value enhances the common statistical measure of frequency of occurrence for term extraction, making it sensitive to a particular type of multi-word terms, the nested terms. The second part, NC-value, gives: 1) a method for the extraction of term context words (words that tend to appear with terms), 2) the incorporation of information from term context words to the extraction of terms.

The influence of substratum topography on bacterial adhesion to polymethyl methacrylate.

Abstract: The effect of substratum roughness on the adhesion of Pseudomonas aeruginosa and Staphylococcus epidermidis was investigated using PMMA. A small increase in Ra values (0.04-1.24 microm) resulted in a significant increase (P<0.05) in bacterial attachment. Subsequent increases in surface roughness (Ra=1.86-7.89 microm) resulted in a decrease in adhesion, although adhesion was still higher than to the smooth surface. When the PMMA surfaces were coated with protein (bovine serum albumin), no difference (P<0.05) could be determined in the amount of protein adsorbed, irrespective of surface topography. However, the influence of the underlying topography on adhesion was still evident. Substratum topography is an important parameter affecting bacterial adhesion to surfaces.

Bacterial alginate biosynthesis - recent progress and future prospects

Abstract: The extracellular polysaccharide alginate has been widely associated with chronic Pseudomonas aeruginosa infections in the cystic fibrosis lung. However, it is clear that alginate biosynthesis is a more widespread phenomenon. Alginate plays a key role as a virulence factor of plant-pathogenic pseudomonads, in the formation of biofilms and with the encystment process of Azotobacter spp.

The earth and beyond: developing primary teachers' understanding of basic astronomical events

Abstract: The demands on the primary school teacher in delivering the National Curriculum in England and Wales at Key Stage 2 (KS 2) for children aged 7‐11 years are considerable. Public debate concerning teacher subject knowledge and understanding, particularly in science, has raised the issue of the need for increased specialism in the primary school. A core element of this debate has focused on how to develop teacher subject knowledge for the effective delivery of the Programme of Study (POS) at KS 2 for practising teachers. This has resulted in the increased provision of in‐service courses in higher education and has also impacted significantly on course content in initial teacher training. This paper relates to the ‘The Earth and Beyond’ POS exploring factors which contribute to developing teachers’ understanding of basic astronomical events. Results indicate that providing teachers with the necessary skills and confidence to teach this aspect of science effectively is much more complex than simply explicating...

Peer Assessment in Undergraduate Programmes

Abstract: Peer assessment was introduced into the assessment strategy of two marketing modules on two undergraduate programmes at Manchester Metropolitan University. A questionnaire was used to elicit responses from a sample of 80 students concerning their attitudes to and experience of, the peer assessment exercise. Students felt that the benefits of peer assessment were: the increase in personal motivation as a result of their active involvement in the assessment process; the opportunity to compare and discuss the assignment, and the opportunity to gain knowledge and develop a greater understanding of the assignment content and assessment process. Criticisms included the effects of personal bias on the marks awarded, the interpretation of criteria and the ability of the students to assess. Some students regarded peer assessment as an incentive to perform, while others saw it as an unfair system that lacked objectivity. Over half the sample regarded assessment as solely a role for the tutor. The research ...

A five year physiological case study of an Olympic runner.

Abstract: OBJECTIVE: To study physiological changes caused by long term endurance training in a world class female distance runner, and to compare these changes with alterations in 3000 m running performance. METHODS: The subject underwent regular physiological assessment during the period 1991-1995. Physiological measures made included body composition, maximal oxygen uptake (VO2MAX), running economy, and lactate threshold. In addition, the running speed at VO2MAX was estimated. Test protocols, laboratory equipment, and laboratory techniques used were the same for each test session. RESULTS: The 3000 m race performance improved by 8% from 1991 to 1993 after which it stabilised. In contrast, VO2MAX fell from 1991 (73 ml/kg/min) to 1993 (66 ml/kg/min). Submaximal physiological variables such as lactate threshold (from 15.0 to 18.0 km/h) and running economy (from 53 ml/kg/min to 48 ml/kg/min at 16.0 km/h) improved over the course of the study. Despite no increase in VO2MAX, the reduction in the oxygen cost of submaximal running caused the estimated running speed at VO2MAX to increase from 19.0 km/h in 1991 to 20.4 km/h in 1995. CONCLUSIONS: Improvement in 3000 m running performance was not caused by an increase in VO2MAX. Rather, the extensive training programme adopted, together perhaps with physical maturation, resulted in improvements in submaximal fitness factors such as running economy and lactate threshold. These adaptations improved the running speed estimated to be associated with VO2MAX, and resulted in improved 3000 m running performance.

The validity of the lactate minimum test for determination of the maximal lactate steady state

Abstract: The validity of the lactate minimum test for determination of the maximal lactate steady state. Med. Sci. Sports Exerc., Vol. 30, No. 8, pp. 1304-1313, 1998.Purpose:The purpose of this study was to investigate the validity of the lactate minimum test([Lac−]BMIN) in the determination of the v

Noise versus Access: The Impact of an Airport in an Urban Property Market

Abstract: The effects of a major airport are unlikely to exhibit a uniform spatial distribution. The benefits to industries and individual households may extend well beyond the local economy, whereas many of the costs are spatially concentrated in the immediate environment. In particular, the problems of noise and traffic generation can be expected to fall principally upon adjacent populations. This paper addresses the general question of whether the costs to local economies of airport proximity, which are in the nature of externalities, outweigh the benefits of access, employment and improved infrastructure. Based on data relating to Manchester airport and its surrounding areas, the specific approach adopted in the paper involves an investigation of the extent to which such proximity effects are capitalised into residential property prices. Our results provide some evidence to suggest that circumstances may exist where positive attributes, such as improved access and employment opportunities, may be more highly va...

Consumption and the Postmodern City

Abstract: Probes into the consumer culture in the postmodern city through a survey of a population that recently moved into refurbished homes in downtown Manchester, England. Attraction to the middle class of culturally based urban regeneration; Cultural consumption and lifestyle; Sociology of contemporary cultural change.

On Riemann solvers for compressible liquids

Abstract: A number of Riemann solvers are proposed for the solution of the Riemann problem in a compressible liquid. Both the Tait and Tammann equations of state are used to describe the liquid. Along with exact Riemann solvers. a detailed description of a primitive variable Riemann solver, a two-shock Riemann solver, a two-rarefaction Riemann solver and an extension to the HLL Riemann solver, namely the HLLC Riemann solver, are presented. It is shown how these Riemann solvers may be implemented into Godunov-type numerical methods. The appropriateness of each of the Riemann solvers for a number of flow situations is demonstrated by applying Godunov's method to some revealing shock tube test problems

Can There Be Criteria for Selecting Research Criteria?—A Hermeneutical Analysis of an Inescapable Dilemma:

Abstract: For some time now qualitative researchers have been debating the implications of the cri sis of representation in social and educational research. The untenability of any notion of absolute truth has left us with the problem of determining the status of research findings. Considerable attention has been devoted to finding criteria that will enable judgments to be made between competing research claims. However, this leads to a second, equally intractable problem: How can we determine which set of putative criteria to adopt? This article analyzes the nature of criteria in qualitative research from a hermeneutical per spective, arguing that criteria can only be located in the interaction between research findings and the critical reader of those findings. It is suggested that it is both illogical and pointless to attempt to predetermine a definitive set of criteria against which all qualitative research should be judged.

A field study of age and gender differences in habitual adult sleep

Abstract: The sleep of 52 healthy paid subjects (23 male) divided into three age-bands (20–34, 35–49 and 50–70 y) were recorded at night in their homes for a total of 190 subject-nights while following their normal daily activities and habitual sleep-wake schedule. There was a shortening in both nocturnal total sleep period and total sleep time (TST) with age, the oldest group sleeping 46 min less than the youngest. Also, the mid-point of sleep occurred 32 min earlier in the oldest group compared with the youngest group. The reduction in TST with age was due, in part, to increased wake periods within sleep. The youngest subjects showed more Movement Time which progressively decreased with age while the amount of stage 1 increased with age. The amount of slow-wave sleep (SWS, stages 3+4) was reduced, stage 4 was more than halved, while REM was slightly reduced with age. There were far fewer significant gender differences in the sleep variables: males, particularly in the middle and oldest age bands, had more stage 1 than females, while females had more SWS, particularly stage 3, than males. In general, despite relatively limited subject selection criteria, there was good agreement with previous laboratory-based normative sleep values for the effect of age and gender.

Ecological effects of atmospheric reactive nitrogen deposition on semi-natural terrestrial ecosystems

Abstract: Evidence that enhanced reactive nitrogen deposition is affecting semi-natural terrestrial ecosystems comes from historic increases in plant tissue N concentrations, correlations between tissue N concentrations and present-day total atmospheric N deposition, changes in plant amino-acid composition and effects on N assimilation. The ecological significance of such changes in biomarkers is uncertain.This paper explores the ecological significance of reactive atmospheric N deposition through a review of previous experimental findings and new experimental evidence from an acidic and a calcareous grassland, both showing phosphorus limitation, and a N-limited Calluna vulgaris (L.) Hull heathland in upland Britain. Nitrogen addition in the range 0-20 g N m -2 yr -1 initially (years 0-4) increased the growth of Calluna and a decline in some subordinate species. In subsequent years, shoot extension was not stimulated, but winter injury was observed from 1993 onwards, suggesting a strong interaction between N supply and climatic conditions. By contrast, the grasslands showed a small decrease in the cover of higher plants in later years (6-7) of the experimental treatments (0-14 g N m -2 yr -1 ) and no growth stimulation. All N treatments reduced the bryophyte cover in the acidic grassland. There were marked effects on below-ground processes, including a sustained stimulation of N mineralization in the grassland soils, and an increase in the bacterial utilization of organic substrates in the heathland, as measured in BIOLOG plates. The results strongly suggest the importance of atmospheric N deposition on microbially driven processes in soils, and are discussed in relation to the scale of potential ecosystem changes and their reversibility by pollution abatement.

Mammal distributions in the western Mediterranean: the role of human intervention

Abstract: The natural distribution of the 17 non-flying mammal species occurring wild in both the Maghreb (north-west Africa) and Iberia (south-west Europe) is considered. It is concluded that only four species – Red Fox Vulpes vulpes, Wild Boar Sus scrofa, Wild Cat Felis silvestris and Otter Lutra lutra – are native to both regions, while another three – Red Deer Cervus elaphus, Brown Bear Ursus arctos and Aurochs Bos primigenius – were native to North Africa until the mid-Holocene but have probably died out naturally. Algerian Hedgehog Atelerix algirus, Barbary Ape Macaca sylvanus, Genet Genetta genetta and Egyptian Mongoose Herpestes ichneumon are widely accepted as introductions to Europe from North Africa. The remaining six species, and Red Deer now found in Africa, were also probably introduced – Rabbit Oryctolagus cuniculus, Weasel Mustela nivalis, Wood Mouse Apodemus sylvaticus and Lesser White-toothed Shrew Crocidura russula from Europe to Africa; Algerian Mouse Mus spretus from Africa to Europe; Savi’s Pygmy Shrew Suncus etruscus perhaps from the eastern Mediterranean to both Iberia and the Maghreb. There are two Maghrebi species which, although not found in Europe, are more closely related to Palaearctic than to Afrotropical species: Garden Dormouse Eliomys melanurus, probably native to north-west Africa, although possible augmentation of the natural population cannot be ruled out, and Whitaker’s Shrew Crocidura whitakeri, a North African endemic. Removal of so many species of European provenance from the list of mammals native to north-west Africa should not be considered to weaken its position as part of the Palaearctic zoogeographical region. Bats and other, non-mammalian, taxa illustrate the clear faunal relationship between the Maghreb and south-west Europe, whilst emphasizing its distinction from subsaharan Africa.

SDML: A Multi-Agent Language for Organizational Modelling

Abstract: A programming language which is optimized for modelling multi-agent interaction within articulated social structures such as organizations is described with several examples of its functionality. The language is SDML, a strictly declarative modelling language which has object-oriented features and corresponds to a fragment of strongly grounded autoepistemic logic. The virtues of SDML include the ease of building complex models and the facility for representing agents flexibly as models of cognition as well as modularity and code reusability. Two representations of cognitive agents within organizational structures are reported and a Soar-to-SDML compiler is described. One of the agent representations is a declarative implementation of a Soar agent taken from the Radar-Soar model of Ye and Carley (1995). The Ye-Carley results are replicated but the declarative SDML implementation is shown to be much less computationally expensive than the more procedural Soar implementation. As a result, it appears that SDML supports more elaborate representations of agent cognition together with more detailed articulation of organizational structure than we have seen in computational organization theory. Moreover, by representing Soar-cognitive agents declaratively within SDML, that implementation of the Ye-Carley specification is necessarily consistent and sound with respect to the formal logic to which SDML corresponds.

Retention of oral microorganisms on cobalt-chromium alloy and dental acrylic resin with different surface finishes.

Abstract: STATEMENT OF PROBLEM: The effect of surface finish of dental materials on the subsequent contamination by microorganisms. PURPOSE: This study compared the retention of Streptococcus oralis, Actinomyces viscosus, and Candida albicans on polished, sandblasted (fine and coarse) and electrobrightened cobalt-chromium alloy and dental acrylic resin to assess in vitro the effect of such techniques on prosthesis contamination. MATERIAL AND METHODS: Standardized cell suspensions were incubated with test materials for 1 hour at 37 degrees C, after which retained cells were counted by using image analysis (percentage area of a microscopic field covered by cells). RESULTS: Retention of bacterial cells was substantial (S oralis 12% to 20% and A viscosus 9% to 16%) irrespective of surface finish. Maximal retention was observed on cobalt-chromium alloy that had undergone fine sandblasting and electrobrightening (P < .01). For C albicans, an increase in surface roughness (0.15 to 3.53 microns) resulted in an increase in retention (3% to 9%). CONCLUSION: Cell size and the type of roughening significantly affected the retention of microorganisms on surfaces. Electrobrightening of cobalt-chromium alloy did not reduce the surface roughness or subsequent cell attachment.

Children and Citizenship in Britain: A Case for a Socially Interdependent Model of Citizenship

Abstract: In the 1980s and 1900s there has been a substantial amount of discussion around notions of citizenship. Given the marginal treatment of children in mainstream sociology in the 1980s, it is small wo...

E-mail: A qualitative research medium for interviewing?

Abstract: This paper explores the opportunities that developments in computer-mediated Communication (CMC) are making available for social science research. In particular, the use of electronic mail (e-mail) is proposed as a viable and valuable research medium for conducting qualitative interviews, alongside the traditional face-to-face interview. The practical, methodological and conceptual implications of e-mail interviewing are explored. In addition, important ethical dilemmas concerning informed consent, privacy, confidentiality, protection from harm, interpretation and ownership of material are discussed.

Combining Work and Study: an empirical study of full‐time students in school, college and university∗

Abstract: Increasing proportions of students in full‐time education are routinely combining work with study which muddies the waters of the school‐to‐work transition. It is no longer appropriate to divide education and work and it is more useful to conceptualise the school‐to‐work transition as part of a life‐time learning process of transferable skills accrual. In a work experience undertaken for economic and social reasons students learn to reconcile the conflicting demands of work and study. Given the funding crisis in higher education and the likely exemption of young people from the National Minimum Wage, students can be expected to become even more entrenched as cheap and flexible labour. ∗A revised version of the paper presented at the ILM Conference 1997 ‘Understanding the school‐to‐work transition’ 16‐17 June, Aberdeen.

Measurement of exercise dependence in bodybuilders.

Abstract: OBJECTIVE: The purpose of this study was to explore exercise dependence in bodybuilders, and undertake preliminary validation of a measurement instrument EXPERIMENTAL DESIGN: A comparative analysis of self-report indices between groups PARTICIPANTS: Forty-seven bodybuilders, 31 individuals who weight trained for general fitness purposes and 24 weightlifters participated in the study MEASURES: Each subject completed the following: demographic information, bodybuilding-specific versions of the social identity and exclusivity scales of the Athletic Identity Measurement Scale, the physical strength and body attractiveness subscales of the Physical Self-Perception Profile, a short form of the Marlowe-Crowne Social Desirability Scale, and a 9-item Bodybuilding Dependence Scale RESULTS: Factor analysis on the BDS revealed 3 subscales (social dependency, training dependency and mastery) which accounted for 684% of the variance Internal consistency was satisfactory for each subscale (Chronbach's alpha = 076, 075 and 078 respectively) The BDS social dependency and PSPP body attractiveness scores of the bodybuilders were higher than those of the weightlifters, whose scores were higher than those of the fitness trainers The bodybuilders scored higher on both AIMS subscales than the other groups The bodybuilders and weightlifters scored higher on PSPP physical strength than the fitness trainers BDS social dependency correlated with both AIMS and both PSPP subscales, and BDS training dependency correlated with AIMS exclusivity All three BDS subscales correlated with training frequency Discriminant analysis found the combination of AIMS social identity, BDS social dependency and years training experience enabled correct classification of 92% of the respondents CONCLUSIONS: These results support the construct and concurrent validity of the BDS social dependency subscale, but do not wholly support the validity of the other two subscales

Shortening-induced force depression in human adductor pollicis muscle

Abstract: 1. The effects of single isovelocity shortening contractions on force production of the electrically stimulated human adductor pollicis muscle were investigated in seven healthy male subjects. 2. Redeveloped isometric force immediately following isovelocity shortening was always depressed compared with the isometric force recorded at the same muscle length but without preceding shortening. The maximal isometric force deficit (FD) was (mean +/- S.E.M.) 37 +/- 2% after 38 deg of shortening at 6.1 deg s-1. 3. The FD was positively correlated with angular displacement (r2 > 0.98) and decreased with increasing velocity of the shortening step. Stimulation at 20 Hz instead of 50 Hz reduced absolute force levels during the contractions to about 73% and the FD was decreased to a similar extent. Eighty-nine per cent of the velocity-related variation in the FD could be explained by the absolute force levels during shortening. 4. FD was largely abolished by allowing the muscle to relax briefly (approximately 200 ms), a time probably too short for significant metabolic recovery. 5. At all but the highest velocities there was a linear decline in force during the latter part of the isovelocity shortening phase, suggesting that the mechanisms underlying FD were active during shortening. 6. Our results show that shortening-induced force deficit is a significant feature of human muscle working in situ and is proportional to the work done by the muscle-tendon complex. This finding has important implications for experimental studies of force-velocity relationships in the intact human.