David A Jones

David A Jones
Manchester Metropolitan University | MMU · Department of Life Sciences

BSc PhD

About

356
Publications
94,023
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21,773
Citations
Introduction
Although well retired now I am still involved in three areas of research. In Manchester I am collaborating with Hans Degens and Jamie McPhee, the main areas of interest being the effects of ageing on muscle and physical performance, mostly in real people, but we have also explored the reasons why older muscle appears to more resistant to stretch using single skinned fibres. The other main area has been helping with research in Chulee's lab in Thailand. Here the research centres around the benefits of slow breathing and use of the BreatheMAX device helping with secretion clearance for intubated patients, but also as a very effective way of reducing blood pressure. I have also been collaborating with the Sports University, Kaunas, looking at the consequences of eccentric exercise.
Additional affiliations
October 2004 - present
Manchester Metropolitan University
Position
  • Professor Emeritus
Description
  • Emeritus Professor of muscle Physiology since 2009
October 1993 - October 2009
University of Birmingham
Position
  • Professor
Description
  • From 2004 I had joint appointments at Birmingham and MMU
October 1976 - October 1993
University College London
Position
  • Professor (Associate)

Publications

Publications (356)
Article
Full-text available
The purposes of this study were to investigate the muscle-tendon unit stiffness response and to compare the stiffness with those of other indirect markers induced by two bouts of unaccustomed eccentric exercise. Eleven untrained men performed two bouts of 200 maximal eccentric contractions of the right quadriceps 4 weeks apart. Changes in stiffness...
Article
Full-text available
Older people have an increased risk of falling during locomotion, with falls on stairs being particularly common and dangerous. Step going (i.e., the horizontal distance between two consecutive step edges) defines the base of support available for foot placement on stairs, as with smaller going, the user's ability to balance on the steps may become...
Article
Full-text available
Background and Objectives: Muscle fatigue is characterised by (1) loss of force, (2) decreased maximal shortening velocity and (3) a greater resistance to stretch that could be due to reduced intracellular Ca2+ and increased Pi, which alter cross bridge kinetics. Materials and Methods: To investigate this, we used (1) 2,3-butanedione monoxime (BDM)...
Article
Full-text available
Magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) were used to assess changes in thigh lean mass in septuagenarian men and women during a 5-year longitudinal study. Twenty-four older individuals participated in the study (10 men: 71.6 ± 4.1 years; 14 women: 71.3 ± 3.2 years at baseline). Thigh MRI and whole-body DXA scans...
Article
New finding: What is the central question of this study? Does low frequency muscle fatigue, indicate a failure of excitation-contraction coupling after eccentric exercise, or is simply due to a change in muscle length? What is the main finding and its importance? The low to high frequency ratio was relatively insensitive to changes in muscle lengt...
Article
Full-text available
Objective: Sarcopenia, defined as loss of both muscle strength and mass, is associated with inferior clinical outcomes and quality of life (QoL) in chronic kidney disease, but its effects are unknown in kidney transplantation. Obesity confers increased mortality risk and compromises QoL in kidney transplant recipients (KTRs), but the impacts of sa...
Article
Full-text available
The purpose of this study was to determine the extent to which low‐frequency fatigue (LFF) accounts for the loss of quadriceps strength and time course of recovery following a series of drop jumps (DJs). Seventeen female subjects (20.8 ± 1.4 years) undertook 100 DJs which were repeated 4 weeks later. Maximum isometric torque (MIT) and the ratio of...
Article
Full-text available
Introduction: Stair descent is a physically demanding activity of daily life and common risk for falls. Age-related deteriorations in ankle joint capacities make stair descent particularly challenging for older adults in built environments, where larger rise steps are encountered. Exercise training may allow older adults to safely cope with the hi...
Article
Full-text available
Objectives: To determine the role of primary and secondary damage in the variation between people of maximum voluntary contraction (MVC) torque recovery following eccentric exercise and the faster recovery following a repeated bout of exercise. Methods: Twenty-one healthy, active but untrained young female subjects undertook eccentric exercise o...
Article
Full-text available
Objectives Slow loaded breathing training has been shown to reduce resting blood pressure (BP) in isolated systolic hypertension (ISH), but it is not known whether this also reduces their exaggerated BP responses to exercise. Methods The study was a randomized controlled trial with block allocation stratified by sex. Twenty ISH patients (68 ± 5 yr...
Article
Full-text available
New findings: What is the central question of this study? Human frailty is characterized by accumulated health complaints, including medical conditions, low physical and psychological function and social components. It is currently unknown whether the condition is associated with neuromuscular changes detectable by electrophysiology obtained from...
Article
Full-text available
Purpose To determine how muscle stiffness and pain which develop after eccentric exercise are affected by gentle stretching and repeated exercise. Methods Twenty-one healthy female participants undertook eccentric exercise of the elbow flexors and changes in resting elbow flexion angle (REFA; a measure of muscle stiffness), pain on stretch scale,...
Article
Full-text available
The evidence concerning the effects of exercise in older age on motor unit (MU) numbers, muscle fiber denervation and reinnervation cycles is inconclusive and it remains unknown whether any effects are dependent on the type of exercise undertaken or are localized to highly used muscles. MU characteristics of the vastus lateralis (VL) were assessed...
Article
Full-text available
Study design: A prospective, randomized crossover trial. Objectives: To evaluate the efficacy of the combination of incentive spirometry with oscillation (OIS) and positive expiratory pressure with oscillation (OPEP) to promote secretion clearance in intubated patients with cervical spinal cord injury. Setting: Spinal cord unit, tertiary care...
Article
Full-text available
Objectives: Faster recovery of postexertional dyspnea might enable chronic obstructive pulmonary disease (COPD) patients to undertake more physical activity. The purpose of this study was to determine whether breathing with a positive expiratory load to reduce dynamic hyperinflation (DH) would hasten recovery. Methods: Thirteen male COPD patient...
Conference Paper
Exercise is a key intervention for pulmonary rehabilitation but it is difficult to find simple exercise for COPD patients with limited space and equipment at home. Marching on the spot raising arms (> 90o) and thigh (>70o) high (Spot Marching Exercise, SME) has been developed. This study aimed to determine whether home SME can improve physical perf...
Conference Paper
Dynamic hyperinflation is a major cause of dysnea limiting exercise in COPD wich could be reduce by positive expiratory pressure (PEP) breathing. We have developed a flow-dependent conical PEP device fitting into a mask (CPEP-mask) which would be more convenient to use during whole body exercise and daily physical activity. The aim of the study was...
Article
Full-text available
Background: A flow-dependent conical positive expiratory pressure (PEP) resistor incorporated into a oronasal mask was developed, which might reduce dyspnea and dynamic hyperinflation and increase exercise endurance for patients with COPD. We reported here the flow-pressure relationships and the safety and suitability of the device when used by he...
Article
Full-text available
Background : It is important to encourage lung inflation to prevent postsurgical pulmonary complications and we compared three breathing techniques that place different emphasis on inspiratory flow and breath-holding. Methods: Fourteen healthy older people (69 ± 3.6 yrs) used diaphragmatic breathing (DB), Triflo II (TF), and a water pressure thresh...
Article
Full-text available
Purpose: Current methods for estimating muscle motor unit (MU) number provide values which are remarkably similar for muscles of widely differing size, probably because surface electrodes sample from similar and relatively small volumes in each muscle. We have evaluated an alternative means of estimating MU number that takes into account differenc...
Article
Full-text available
Key points: The age-related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. Enlarged motor units h...
Chapter
A comprehensive multi-disciplinary overview of the very latest research on ageing, concentrating on three major themes: active ageing, design for ageing well and the relationship between ageing and socio-economic development.
Article
Full-text available
The contributions of fibre atrophy, fibre loss, in situ specific force and voluntary activation to weakness in sarcopenia remain unclear. To investigate, forty older (20 women; age 72±4yrs) and 31 younger adults (15 women, age 22±3yrs) completed measurements. The knee extensor maximal voluntary torque (MVC) was measured as well as voluntary activat...
Chapter
This chapter discusses strategies that older and younger people employ to negotiate stairs based on experiments performed on an instrumented staircase in lab environment aiming at identifying ways to reduce stair fall risk for the elderly. Stair negotiation was found to be more demanding for the knee and ankle joint muscles in older than younger ad...
Presentation
Full-text available
Background: Premature airway closure during exercise is common in elderly leading to dyspnea and exercise intolerance [1]. Positive expiratory pressure (PEP) can reduce airway closure and dyspnea but may lead to CO2 retention affecting cardiovascular function. We investigated the effects and safety of a new conical-PEP (CPEP) device on cardiopulmon...
Article
Full-text available
Purpose: The purpose of this study was to compare the benefits and possible problems of 4 weeks stretching when taken to the point of pain (POP) and to the point of discomfort (POD). Methods: Twenty-six physically active women (20 ± 1.1 years) took part in group-based stretching classes of the hamstring muscles, 4 times per week for 4 weeks, one...
Article
Full-text available
Purpose: This study evaluated the acute effects of two different stretch intensities on muscle damage and extensibility. Methods: Twenty-two physically active women (age 20 ± 1.0 years) were divided into two matched groups and undertook eight sets of 30-s passive hamstring stretching. One group stretched to the point of discomfort (POD) and the...
Article
Full-text available
Isolated systolic hypertension (ISH) is the most common form of hypertension in older people. It is characterized by increased resting systolic blood pressure (sBP) and increased sBP in response to exercise. It has previously been shown that slow breathing training reduces resting sBP, and the objective of the present study was to determine whether...
Article
Full-text available
Background: As muscle capillarization is related to the oxidative capacity of the muscle and the size of muscle fibres, capillary rarefaction may contribute to sarcopenia and functional impairment in older adults. Therefore, it is important to assess how ageing affects muscle capillarization and the interrelationship between fibre capillary supply...
Article
Full-text available
BACKGROUND: As muscle capillarization is related to the oxidative capacity of the muscle and the size of muscle fibres, capillary rarefaction may contribute to sarcopenia and functional impairment in older adults. Therefore, it is important to assess how ageing affects muscle capillarization and the interrelationship between fibre capillary supply...
Article
Full-text available
This paper presents examples of hysteresis from a broad range of scientific disciplines and demonstrates a variety of forms including clockwise, counterclockwise, butterfly, pinched and kiss-and-go, respectively. These examples include mechanical systems made up of springs and dampers which have been the main components of muscle models for nearly...
Conference Paper
Full-text available
Age-related changes in contractile properties are of considerable interest, but relatively little is known about the response of young or old muscle to stretch. Particularly, the decay of force may give information about the kinetics of the various cross bridge states. At the end of a ramp-and-hold stretch, force decays towards a value somewhat abo...
Conference Paper
Full-text available
Age-related changes in contractile properties are of considerable interest, but relatively little is known about the response of young or old muscle to stretch. Particularly, the decay of force may give information about the kinetics of the various cross bridge states. At the end of a ramp-and-hold stretch, force decays towards a value somewhat abo...
Article
Full-text available
Muscle motor unit numbers decrease markedly in old age, while remaining motor units are enlarged and can have reduced neuromuscular junction transmission stability. However, it is possible that regular intense physical activity throughout life can attenuate this remodeling. The aim of this study was to compare the number, size, and neuromuscular ju...
Article
Objective: To determine whether slow loaded breathing training can enhances blood pressure reduction associated with conventional medication. Design and method: Randomised controlled trialThirty patients (66 ± 4 years) with isolated systolic hypertension and managed with conventional medication, were randomized into loaded breathing (LB: 6 breat...
Article
Introduction and Objective: Arm movement to shoulder height adds to the mechanical load on respiratory muscles by reducing chest wall compliance and provides more of an exercise challenge for COPD patients than using legs predominantly. We have developed a new simple combined arm and leg exercise test (spot marching test, SMT) and have compared car...
Article
Questions: Dyspnea is a major factor limiting exercise for people with COPD and is associated with dynamic hyperinflation (DH). Can breathing with a positive expiratory pressure (PEP) accelerate the recovery of exertional dyspnea? Can PEP reduce post-exercise DH? Are there drawbacks or risks of PEP breathing, such as CO2 retention? Participants: Th...
Article
Background: Premature airway closure during exercise is common in elderly leading to dyspnea and exercise intolerance [1]. Positive expiratory pressure (PEP) can reduce airway closure and dyspnea but may lead to CO2 retention affecting cardiovascular function. We investigated the effects and safety of a new conical-PEP (CPEP) device on cardiopulmon...
Poster
Full-text available
การพัฒนาอุปกรณ์ก่อแรงดันบวกแบบใหม่สำหรับการออกกำลังกายในผู้ป่วยโรคปอดอุดกั้นเรื้อรัง (Development of positive expiratory pressure device for exercising in COPD) ฉัตรชัย พิมพศักดิ์ 1, ชุลี โจนส์ 2*, David A Jones 3 Chatchai Phimphasak 1, Chulee Jones.Assoc.Prof 2*, David A Jones.Prof 3 1 นักศึกษาปริญญาเอก สาขาวิทยาศาสตร์การเคลื่อนไหวของมนุษย์ คณะเทค...
Article
Full-text available
Voluntary control of skeletal muscle enables humans to interact with and manipulate the environment. Lower muscle mass, weakness and poor coordination are common complaints in older age and reduce physical capabilities. Attention has focused on ways of maintaining muscle size and strength by exercise, diet or hormone replacement. Without appropriat...
Article
Introduction: Isolated systolic hypertension (ISH) is very common but difficult to manage with conventional medication. We investigated whether slow breathing training, with and without an inspiratory load, could reduce the resting blood pressure of older well managed ISH patients. Methods: Thirty ISH patients (66±4 years), were randomized into...
Article
Full-text available
Background: Physical fatigue is debilitating and common among kidney transplant recipients (KTRs). This study investigated the mechanistic aetiology of physical fatigue in this setting through examinations of muscle mass, muscular and cardiovascular function, and perceived exertion. The incidence of physical fatigue, its association with quality o...
Article
Introduction: Exercise is generally regarded as beneficial for health but the consequent increases in blood pressure might pose a risk for hypertensive subjects. This study was to determine the blood pressure responses to dynamic exercise and sustained handgrip in patients with isolated systolic hypertension (ISH) who were stable on medication. M...
Article
Objective: This study investigated differences in cardiorespiratory fitness, muscular function, perceived exertion, and anxiety/depression between patients and healthy controls (HCs) and assessed which of these variables may account for the fatigue experienced by patients. Methods: Fatigue was measured in 48 antineutrophil cytoplasmic antibody-a...
Article
Full-text available
Introduction: The anterior thigh muscles are particularly susceptible to muscle loss and weakness during ageing, but it remains unclear how this is associated with changes to neuromuscular structure and function in terms of motor unit (MU) number, size and MU potential (MUP) stability. Methods: Intramuscular and surface electromyographic (EMG) s...
Research
Full-text available
Part of the unpublished series of chapters on Growth Development and Ageing
Research
Full-text available
Unpublished chapters on Growth Development and Ageing
Research
Full-text available
Part of a series of chapters on Growth Development and Ageing
Research
Full-text available
This is an unpublished draft of a book chapter on Growth Development and Ageing
Article
While it is undoubtedly true that some aspects of ageing, such as greying of hair, vary considerably between people we would like to suggest that this is not true for all body systems, certainly not for muscle and, most likely, not for ˙VO2max . The scatter of data seen with older subjects does not necessarily indicate highly individualistic rates...