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Prof David Howard's Outputs (108)

FES-UPP : a flexible functional electrical stimulation system to support upper limb functional activity practice (2018)
Journal Article

There is good evidence supporting highly intensive, repetitive, activity-focused, voluntary-initiated practice as a key to driving recovery of upper limb function following stroke. Functional electrical stimulation (FES) offers a potential mechanism... Read More about FES-UPP : a flexible functional electrical stimulation system to support upper limb functional activity practice.

Performance of optimised prosthetic ankle designs that are based on a hydraulic variable displacement actuator (VDA) (2017)
Journal Article
Gardiner, J., Bari, A., Kenney, L., Twiste, M., Moser, D., Zahedi, S., & Howard, D. (2017). Performance of optimised prosthetic ankle designs that are based on a hydraulic variable displacement actuator (VDA). IEEE Transactions on Neural Systems and Rehabilitation Engineering, 25(12), 2418-2426. https://doi.org/10.1109/TNSRE.2017.2763999

Current energy storage and return (ESR) prosthetic
feet only marginally reduce the cost of amputee locomotion
compared to basic solid ankle cushioned heel (SACH) feet,
possibly due to their lack of push-off at the end of stance. To our knowledge,... Read More about Performance of optimised prosthetic ankle designs that are based on a hydraulic variable displacement actuator (VDA).

Estimating the material properties of heel pad sub-layers using inverse finite element analysis (2016)
Journal Article
Ahanchian, N., Nester, C., Howard, D., Ren, L., & Parker, D. (2016). Estimating the material properties of heel pad sub-layers using inverse finite element analysis. Medical Engineering and Physics, 40, 11-19. https://doi.org/10.1016/j.medengphy.2016.11.003

Detailed information about the biomechanical behaviour of plantar heel pad tissue contributes to our understanding of load transfer when the foot impacts the ground. The objective of this work was to obtain the hyperelastic and viscoelastic material... Read More about Estimating the material properties of heel pad sub-layers using inverse finite element analysis.

Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off (2016)
Journal Article
Weinert-Aplin, R., Howard, D., Twiste, M., Jarvis, H., Bennett, A., & Baker, R. (2017). Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off. Medical Engineering and Physics, 39, 73-82. https://doi.org/10.1016/j.medengphy.2016.10.005

Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This... Read More about Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off.

Crowd-sourced amputee gait data : a feasibility study using YouTube videos of unilateral trans-femoral gait (2016)
Journal Article

Collecting large datasets of amputee gait data is notoriously difficult. Additionally, collecting data on less prevalent amputations or on gait activities other than level walking and running on hard surfaces is rarely attempted. However, with the we... Read More about Crowd-sourced amputee gait data : a feasibility study using YouTube videos of unilateral trans-femoral gait.

A review of the design and clinical evaluation of the ShefStim array-based functional electrical stimulation system (2016)
Journal Article

Functional electrical stimulation has been shown to be a safe and effective means of correcting foot drop of central neurological origin. Current surface-based devices typically consist of a single channel stim- ulator, a sensor for determining gait... Read More about A review of the design and clinical evaluation of the ShefStim array-based functional electrical stimulation system.

Dealing with time-varying recruitment and length in Hill-type muscle models (2016)
Journal Article
Hamouda, A., Kenney, L., & Howard, D. (2016). Dealing with time-varying recruitment and length in Hill-type muscle models. Journal of Biomechanics, 49(14), 3375-3380. https://doi.org/10.1016/j.jbiomech.2016.08.030

Hill-type muscle models are often used in muscle simulation studies and also in the design
and virtual prototyping of functional electrical stimulation systems. These models have to
behave in a sufficiently realistic manner when recruitment level a... Read More about Dealing with time-varying recruitment and length in Hill-type muscle models.

A flexible finite state controller for upper limb functional electrical stimulation (2016)
Presentation / Conference
Sun, M., Kenney, L., Smith, C., Waring, K., Luckie, H., & Howard, D. (2016, June). A flexible finite state controller for upper limb functional electrical stimulation. Poster presented at 20th Annual Conference of the International Functional Electrical Stimulation Society, La Grande-Motte, France

This paper reports on a flexible finite stage machine (FSM) controller for the real-time control of functional electrical stimulation (FES) during upper limb rehabilitation, and an associated setup Graphical User Interface (GUI) guides clinical users... Read More about A flexible finite state controller for upper limb functional electrical stimulation.

A fast inverse dynamics model of walking for use in optimisation studies (2016)
Journal Article
Salehi, S., Ren, L., & Howard, D. (2016). A fast inverse dynamics model of walking for use in optimisation studies. Computer Methods in Biomechanics and Biomedical Engineering, 19(11), 1201-1209. https://doi.org/10.1080/10255842.2015.1124267

Computer simulation of human gait, based on measured motion data, is a well-established technique in biomechanics. However, optimisation studies requiring many iterative gait cycle simulations have not yet found widespread application because of thei... Read More about A fast inverse dynamics model of walking for use in optimisation studies.

Transtibial amputee gait efficiency : energy storage and return versus solid ankle cushioned heel prosthetic feet (2016)
Journal Article

Energy storage and return (ESR) feet have long been assumed to promote metabolically efficient amputee gait. However, despite being prescribed for approximately thirty years, there is limited evidence that they achieve this desired function. Here, we... Read More about Transtibial amputee gait efficiency : energy storage and return versus solid ankle cushioned heel prosthetic feet.

A device for characterising the mechanical properties of the plantar soft tissue of the foot (2015)
Journal Article
Parker, D., Cooper, G., Pearson, S., Crofts, G., Howard, D., Busby, P., & Nester, C. (2015). A device for characterising the mechanical properties of the plantar soft tissue of the foot. Medical Engineering and Physics, 37(11), 1098-1104. https://doi.org/10.1016/j.medengphy.2015.08.008

The plantar soft tissue is a highly functional viscoelastic structure involved in transferring load to the human body during walking. A Soft Tissue Response Imaging Device was developed to apply a vertical compression to the plantar soft tissue whils... Read More about A device for characterising the mechanical properties of the plantar soft tissue of the foot.

Meta-analysis of metabolic cost of amputee walking shows only a marginal improvement in cost when using ESR feet compared to conventional SACH feet (2015)
Presentation / Conference
Gardiner, J., Bari, Z., Kenney, L., & Howard, D. (2015, June). Meta-analysis of metabolic cost of amputee walking shows only a marginal improvement in cost when using ESR feet compared to conventional SACH feet. Presented at ISPO World Congress 2015, Lyon, France

Background: Energy storage and return (ESR) prosthetic feet are designed to store strain energy during stance and release that energy during push-off and, hence, promote a more energy efficient gait. However, despite ESR feet being prescribed for app... Read More about Meta-analysis of metabolic cost of amputee walking shows only a marginal improvement in cost when using ESR feet compared to conventional SACH feet.

Novel methods of using accelerometry for upper limb FES control [conference paper] (2015)
Presentation / Conference
Sun, M., Howard, D., Kenney, L., Smith, C., Waring, K., & Luckie, H. (2015, May). Novel methods of using accelerometry for upper limb FES control [conference paper]. Presented at 5th Conference of the International Functional Electrical Stimulation Society (IFESS) UK & Ireland Chapter : Stimulating Technology for the Future, Sheffield, UK

Introduction: Accelerometry offers a low cost, low power solution to measuring body segment angle (BSA) relative to the gravity vector under quasi-static conditions. BSA may be used as an input to a state-machine based, upper limb functional electric... Read More about Novel methods of using accelerometry for upper limb FES control [conference paper].

A forward dynamic modelling investigation of cause-and-effect relationships in single support phase of human walking (2015)
Journal Article
McGrath, M., Howard, D., & Baker, R. (2015). A forward dynamic modelling investigation of cause-and-effect relationships in single support phase of human walking. Computational and Mathematical Methods in Medicine, 2015, 1-9. https://doi.org/10.1155/2015/383705

Mathematical gait models often fall into one of two categories: simple and complex. There is a large leap in complexity between model types, meaning the effects of individual gait mechanisms get overlooked. This study investigated the cause-and-effec... Read More about A forward dynamic modelling investigation of cause-and-effect relationships in single support phase of human walking.