Publications
16 results found
Duffell LD, Mushtaq J, Masjedi M, et al., 2014, The knee adduction angle of the osteo-arthritic knee: A comparison of 3D supine, static and dynamic alignment, KNEE, Vol: 21, Pages: 1096-1100, ISSN: 0968-0160
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- Citations: 6
Kotti M, Duffell LD, Faisal AA, et al., 2014, The Complexity of Human Walking: A Knee Osteoarthritis Study, PLOS ONE, Vol: 9, ISSN: 1932-6203
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- Citations: 10
Duffell LD, Southgate DFL, Gulati V, et al., 2014, Balance and gait adaptations in patients with early knee osteoarthritis, GAIT & POSTURE, Vol: 39, Pages: 1057-1061, ISSN: 0966-6362
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- Citations: 45
Duffell LD, Hope N, McGregor AH, 2014, Comparison of kinematic and kinetic parameters calculated using a cluster-based model and Vicon's plug-in gait, PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART H-JOURNAL OF ENGINEERING IN MEDICINE, Vol: 228, Pages: 206-210, ISSN: 0954-4119
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- Citations: 48
Varma RK, Duffell LD, Nathwani D, et al., 2014, Knee moments of anterior cruciate ligament reconstructed and control participants during normal and inclined walking, BMJ OPEN, Vol: 4, ISSN: 2044-6055
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- Citations: 18
Masjedi M, Duffell LD, 2013, Dynamic analysis of the upper limb during activities of daily living: Comparison of methodologies, Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
Duffell LD, Gulati V, Southgate DFL, et al., 2013, Measuring body weight distribution during sit-to-stand in patients with early knee osteoarthritis, GAIT & POSTURE, Vol: 38, Pages: 745-750, ISSN: 0966-6362
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- Citations: 29
Greenwood NL, Duffell LD, Alexander CM, et al., 2011, Electromyographic activity of pelvic and lower limb muscles during postural tasks in people with benign joint hypermobility syndrome and non hypermobile people. A pilot study, Man Ther
Benign joint hypermobility syndrome (BJHS) is associated with the early development of certain degenerative conditions, which may be associated with altered muscle activity. This pilot study compared muscle activation patterns during postural tasks between people with BJHS who do not have pain and people with normal flexibility (control group). Sixteen subjects aged 22-45 years (8 with BJHS) were selected from a population recruited to a larger study. Electromyographic activity of erector spinae (ES), gluteus medius (GM), and lower limb (rectus femoris (RF), semitendinosus (ST), tibialis anterior (TA) and gastrocnemius lateralis) muscles was assessed, and chosen based on the muscles being tested in the larger study. Subjects carried out 30 s of quiet standing (QS) and one-leg standing (OLS), both with eyes open (EO) and eyes closed (EC). Both groups had significantly more TA activity, and control subjects had significantly more GM activity, during OLS EC compared with QS. GM activity was not significantly different between groups. Compared with the BJHS group, control subjects had significantly less ST activation overall, significantly more ES activity during OLS EC and significantly less RF-ST co-contraction during QS. This study has noted differences in muscle activation patterns between pain-free hypermobile people and control subjects, specifically involving muscles surrounding the pelvis and hip. This pilot data suggests that strategies for stabilising the body during balancing tasks may be relevant to injury risk in people with BJHS. While results need to be verified with a larger subject sample, this study is important in developing new treatments for hypermobile people
Duffell LD, Dharni H, Strutton PH, et al., 2011, Electromyographic activity of the quadriceps components during the final degrees of knee extension, JOURNAL OF BACK AND MUSCULOSKELETAL REHABILITATION, Vol: 24, Pages: 215-223, ISSN: 1053-8127
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- Citations: 4
Duffell LD, Rowlerson AM, Donaldson NDN, et al., 2011, Effects of endurance and strength-directed electrical stimulation training on the performance and histological properties of paralyzed human muscle: A pilot study (vol 42, pg 756, 2010), MUSCLE & NERVE, Vol: 43, Pages: 154-154, ISSN: 0148-639X
Katakura M, Duffell LD, Strutton PH, et al., 2011, Effects of a 60 second maximum voluntary isometric contraction on torque production and EMG output of the quadriceps muscle group, ISOKINETICS AND EXERCISE SCIENCE, Vol: 19, Pages: 13-22, ISSN: 0959-3020
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- Citations: 3
Duffell LD, Rowlerson AM, Donaldson NDN, et al., 2010, EFFECTS OF ENDURANCE AND STRENGTH-DIRECTED ELECTRICAL STIMULATION TRAINING ON THE PERFORMANCE AND HISTOLOGICAL PROPERTIES OF PARALYZED HUMAN MUSCLE: A PILOT STUDY, MUSCLE & NERVE, Vol: 42, Pages: 756-763, ISSN: 0148-639X
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- Citations: 7
Duffell LD, Donaldson NDN, Newham DJ, 2010, Power Output During Functional Electrically Stimulated Cycling in Trained Spinal Cord Injured People, NEUROMODULATION, Vol: 13, Pages: 50-57, ISSN: 1094-7159
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- Citations: 20
Duffell LD, Donaldson NDN, Newham DJ, 2009, Why is the Metabolic Efficiency of FES Cycling Low? (vol 17, pg 263, 2009), IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, Vol: 17, Pages: 605-605, ISSN: 1534-4320
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- Citations: 1
Duffell LD, de N Donaldson N, Newham DJ, 2009, Why is the metabolic efficiency of FES cycling low?, IEEE Trans Neural Syst Rehabil Eng, Vol: 17, Pages: 263-269
The potential benefits of functional electrically stimulated (FES) cycling for people with spinal cord injury (SCI) are limited by the power output (PO) attainable. To understand why PO and metabolic efficiency are low, it is helpful to distinguish the effect of the SCI from the effects of electrical stimulation. The purpose of this study was to determine the performance of electrically stimulated (ES) muscle under simpler conditions and in able-bodied people in order to answer two questions about the causes of the poor efficiency in FES cycling. Fifteen able-bodied subjects (26.6 years, six male) performed 5 min of intermittent isometric quadriceps contractions at 40% maximum voluntary contraction during both voluntary and ES activation. Subsequently, nine of them performed 5 min of ES intermittent concentric contractions at the same intensity. This intermittent quadriceps activation imitated the muscles' activity during FES cycling at 35 rpm. Metabolic measurements were recorded. Input power relative to the integral of torque produced (W/Nm x s) was significantly higher during ES than voluntary isometric contractions. Efficiency of ES concentric contractions was 29.6 +/-2.9%. Respiratory exchange ratio was high during ES (1.00-1.01) compared with voluntary (0.91) contractions. ES is less economic than voluntary exercise during isometric contractions, probably due to the greater activation of fast muscle fibres. However, during ES concentric contractions, efficiency is near to the expected values for the velocity chosen. Thus there are additional factors that affect the inefficiency observed during FES cycling.
Duffell LD, Donaldson NDN, Perkins TA, et al., 2008, Long-term intensive electrically stimulated cycling by spinal cord-injured people: Effect on muscle properties and their relation to power output, MUSCLE & NERVE, Vol: 38, Pages: 1304-1311, ISSN: 0148-639X
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- Citations: 62
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