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A comparative study between two pressure mapping systems: FSA versus Novel Pliance
Abstracts / Clinical Biomechanics 23 (2008) 662–720
comfort, immediate comfort and perceived comfort after walking. A pilot, follow-on study was also conducted to analyse whether the performance of each of the test shoes was comparable to walking whilst running (3.13 ms 1/ 7 mph) on a treadmill. Each individual walking speed was measured with the GAITRiteÒ gait analysis system (CIR Systems Inc., NJ, USA). Nine subjects were chosen for the follow-on investigation; provided the participant was also an active runner and had a proficient treadmill experience. Results Plantar pressure measurements were recorded from under the heel, across the forefoot and under the great toe. Differences were seen between models and between brands in relation to cost. The medium and high cost models from Brands A and B provided a better pressure attention under the heel. Increasing pressure was recorded with rising cost from Brand C. Brand A performed better than Brands B and C under the forefoot. Increasing pressure under the great toe was registered from Brands A and B with rising cost. The opposite was seen from Brand C. Shoe performance was comparable between walking and running trials on a treadmill. No significant difference was observed between shoes and test occasions in terms of comfort. Conclusion Each of the brands performed differently with changes in cost. Therefore, no definitive conclusions with relation to cost and comfort could be made across all three brands. However, it would appear that running shoe performance is not always related to cost. In other words, spending more money on a pair of running shoes will not necessarily mean that they are better than a cheaper pair. References Aerts, P., Ker, R.F., de Clercq, D., Ilsley, D.W., Alexander, R.M., 1995. The mechanical properties of the human heel pad: a paradox resolved. Journal of Biomechanics 28, 1299–1308. Hreljac, A., 2004. Impact and overuse injuries in runners. Medical Science and Sports Exercise 36, 845–849. Lafortune, M.A., Hennig, E., Valiant, G.A., 1995. Tibial shock measured with bone and skin mounted transducers. Journal of Biomechanics 28, 989–993. Robbins, S., Waked, E., 1997. Hazard of deceptive advertising of atheletic footwear. British Journal of Sports Medicine 31, 299–303. doi:10.1016/j.clinbiomech.2008.03.009
A comparative study between two pressure mapping systems: FSA versus Novel Pliance Lynda Cochrane a, Katie Fergus a, Graham P. Arnold a, Geoff Bardsley b, Rami J. Abboud a a
Institute of Motion Analysis and Research (IMAR), University of Dundee, Scotland, United Kingdom
b
669
Wheel Chair and Seating Services, TORT Centre, Ninewells Hospital and Medical School, Scotland, United Kingdom
Keywords: Pressure mapping; Wheelchairs; Seating; Ulceration; Repeatability Background It has been suggested that between 25% and 66% of wheelchair users suffer from pressure sores (Fuhrer et al., 1993). The consequences can be serious, even life-threatening, particularly when not treated in a timely way (O’Connor, 2005). It is essential, therefore, to monitor pressures experienced by this group of patients so that the adverse conditions can be avoided. While pressure mapping systems are considered to be appropriate when a wheelchair cushion is loaded, the performance characteristics of an individual device determine how useful it can be for both clinical and research purposes. Objectives The accuracy and the reliability of the force sensing array (FSA) pressure mapping system were found to be susceptible to the effects of creep, with pressure readings increasing throughout a test period of 30 min. The results indicated that some of these effects could be a product of the software. Differences between repeated runs at the same applied pressure were markedly different. Hence, the aim of this study was to investigate the characteristics of another pressure mapping system, the Novel Pliance, and compare them with the FSA. Methods The Ultra Thin FSA mat and software version 3.1.033 and the Novel Pliance Mobile Expert Online (standard sensors) system with software Expert v8.3 were compared in this study. The default unit used by Novel Pliance is the SI unit Newtons per centimetre squared (N/cm2). The software allows this to be converted to millimetres of mercury (mmHg), matching those of the FSA system and thus enabling comparisons from the two systems to be made. A run was defined as a period of dynamic scanning over 30 min, with the time interval set to sixty seconds. The average and peak pressures reported in each frame were recorded. Once the final frame had been recorded, the air bladder was deflated. This process was carried out five times (runs) for pressures of 40, 60, 80 and 100 mmHg. The FSA system was calibrated between pressures. The Novel system had been calibrated by the manufacturer prior to the study. Results The Novel Pliance system was found to give readings that were consistent over the test period and between
670
Abstracts / Clinical Biomechanics 23 (2008) 662–720
repeated runs. The effects of creep were significantly less marked than with FSA. Differences between measured and applied average pressures ranged from 4% to 6.8% of the applied pressure with the Novel system, compared with a range of 18.4% to 20.2% with FSA. Readings of average pressure with the Novel system increased by up to 3.7% of the initial pressure reading over a period of 30 min compared with 20.9% with FSA. Differences between measured and applied peak pressures ranged from 4.3% to 68.8% of the applied pressure with the FSA system, compared with a range of 3.1– 31.2% with Novel. Averaged over the five runs and the 30-min test period, error in peak pressure for the FSA system was between 28.7% and 56.7% compared with a range of 8.6–18.7% for Novel. Conclusion The superior accuracy and repeatability of the Novel system indicate that it should be considered the pressure mapping device of choice in clinical and research settings. References Fuhrer, M.J., Garber, S.L., Rintala, D.H., Clearman, R., Hart, K.A., 1993. Pressure ulcers in community-resident persons with spinal cord injury: prevalence and risk factors. Archives of Physical Medicine and Rehabilitation 74 (11), 1172–1177. O’Connor, K., 2005. Pressure ulcers. In: DeLisa, J.A., et al. (Eds.), Physical Medicine and Rehabilitation: Principles and Practice, Lippincott Williams & Wilkins 4th ed., vol. 2. pp. 1605–1618.
rider and the horse. For measurements, the pressure measuring pad (Pliance System, Novel) was used directly on the horse’s back. We measured a group of five healthy subjects without earlier riding experience (in a healthy subject we assume normal motor abilities, without the bias of any health deficiency) at the first and the sixth sessions of hippotherapy at the walk. In each session the physiotherapist assisted from behind and corrected the posture of each subject. Results The cycle of pressure distribution in hippotherapy has similar characteristics as the pressures occurring during athletic horse riding. In the first measurement the range of total power is between 568 and 406 N, the maximal pressure varies from 1.31 to 1.84 N m 2 and minimum from 0.38 to 0.44 N m 2. Six hippotherapy sessions later, the results of the second measurement were in the range of total power between 639 and 453 N, the maximal pressure varied from 1.59 to 2.1 N m 2 and minimum from 0.41 to 0.49 N m 2. Discussion The effect of six sessions of training was an increase in forces on the horse’s back, which we assume is due to the increased contact between horse and rider as the excitement and stress of the new situation and movement activity recedes.
doi:10.1016/j.clinbiomech.2008.03.010 doi:10.1016/j.clinbiomech.2008.03.011
Pressure forces created by the contact of a rider’s body on the horse’s back during hippotherapy T. Dvorakova a, Ch Peham b, M. Janura a,b a
Palacky University Olomouc, Department of Biomechanics and Engineering Cybernetics, Faculty of Physical Culture, Czech Republic b University of Veterinary Medicine Vienna, Clinic of Orthopaedics in Ungulates, Austria Introduction One of the most important tasks of a therapist practicing hippotherapy is to induce ‘‘a movement dialogue” between the horse and the client. It takes some time until the client adapts to the movement of the horse. The appropriate movement pattern of the client is built over time. As soon as this happens, we can say that the therapy has a neuro-physiological effect. Aims and method Our study describes how the increasing experience of the rider changes the cyclic pressure distribution between the
Reliability of PressurestatTM for measuring plantar foot pressures in patients with rheumatoid arthritis Jill Firth a, Deborah E. Turner b, Wendy Smith b, Philip S. Helliwell c, Jim Woodburn d a
School of Health Care Studies, University of Leeds, Leeds, United Kingdom b Department of Podiatry, University of Huddersfield, Huddersfield, United Kingdom c Academic Unit of Musculoskeletal Disease, University of Leeds, Leeds, United Kingdom d HealthQWest, Glasgow Caledonian University, Glasgow, Scotland, United Kingdom
Introduction Plantar pressure measurement (PPM) is used to assess foot function and as a screening tool to establish risk for tissue injury in the ‘at risk’ foot. The routine use of PPM is yet to be fully realized and one barrier may be the perceived reliance on costly specialist equipment. More recently, several semi-quantitative PPM systems have been
comfort, immediate comfort and perceived comfort after walking. A pilot, follow-on study was also conducted to analyse whether the performance of each of the test shoes was comparable to walking whilst running (3.13 ms 1/ 7 mph) on a treadmill. Each individual walking speed was measured with the GAITRiteÒ gait analysis system (CIR Systems Inc., NJ, USA). Nine subjects were chosen for the follow-on investigation; provided the participant was also an active runner and had a proficient treadmill experience. Results Plantar pressure measurements were recorded from under the heel, across the forefoot and under the great toe. Differences were seen between models and between brands in relation to cost. The medium and high cost models from Brands A and B provided a better pressure attention under the heel. Increasing pressure was recorded with rising cost from Brand C. Brand A performed better than Brands B and C under the forefoot. Increasing pressure under the great toe was registered from Brands A and B with rising cost. The opposite was seen from Brand C. Shoe performance was comparable between walking and running trials on a treadmill. No significant difference was observed between shoes and test occasions in terms of comfort. Conclusion Each of the brands performed differently with changes in cost. Therefore, no definitive conclusions with relation to cost and comfort could be made across all three brands. However, it would appear that running shoe performance is not always related to cost. In other words, spending more money on a pair of running shoes will not necessarily mean that they are better than a cheaper pair. References Aerts, P., Ker, R.F., de Clercq, D., Ilsley, D.W., Alexander, R.M., 1995. The mechanical properties of the human heel pad: a paradox resolved. Journal of Biomechanics 28, 1299–1308. Hreljac, A., 2004. Impact and overuse injuries in runners. Medical Science and Sports Exercise 36, 845–849. Lafortune, M.A., Hennig, E., Valiant, G.A., 1995. Tibial shock measured with bone and skin mounted transducers. Journal of Biomechanics 28, 989–993. Robbins, S., Waked, E., 1997. Hazard of deceptive advertising of atheletic footwear. British Journal of Sports Medicine 31, 299–303. doi:10.1016/j.clinbiomech.2008.03.009
A comparative study between two pressure mapping systems: FSA versus Novel Pliance Lynda Cochrane a, Katie Fergus a, Graham P. Arnold a, Geoff Bardsley b, Rami J. Abboud a a
Institute of Motion Analysis and Research (IMAR), University of Dundee, Scotland, United Kingdom
b
669
Wheel Chair and Seating Services, TORT Centre, Ninewells Hospital and Medical School, Scotland, United Kingdom
Keywords: Pressure mapping; Wheelchairs; Seating; Ulceration; Repeatability Background It has been suggested that between 25% and 66% of wheelchair users suffer from pressure sores (Fuhrer et al., 1993). The consequences can be serious, even life-threatening, particularly when not treated in a timely way (O’Connor, 2005). It is essential, therefore, to monitor pressures experienced by this group of patients so that the adverse conditions can be avoided. While pressure mapping systems are considered to be appropriate when a wheelchair cushion is loaded, the performance characteristics of an individual device determine how useful it can be for both clinical and research purposes. Objectives The accuracy and the reliability of the force sensing array (FSA) pressure mapping system were found to be susceptible to the effects of creep, with pressure readings increasing throughout a test period of 30 min. The results indicated that some of these effects could be a product of the software. Differences between repeated runs at the same applied pressure were markedly different. Hence, the aim of this study was to investigate the characteristics of another pressure mapping system, the Novel Pliance, and compare them with the FSA. Methods The Ultra Thin FSA mat and software version 3.1.033 and the Novel Pliance Mobile Expert Online (standard sensors) system with software Expert v8.3 were compared in this study. The default unit used by Novel Pliance is the SI unit Newtons per centimetre squared (N/cm2). The software allows this to be converted to millimetres of mercury (mmHg), matching those of the FSA system and thus enabling comparisons from the two systems to be made. A run was defined as a period of dynamic scanning over 30 min, with the time interval set to sixty seconds. The average and peak pressures reported in each frame were recorded. Once the final frame had been recorded, the air bladder was deflated. This process was carried out five times (runs) for pressures of 40, 60, 80 and 100 mmHg. The FSA system was calibrated between pressures. The Novel system had been calibrated by the manufacturer prior to the study. Results The Novel Pliance system was found to give readings that were consistent over the test period and between
670
Abstracts / Clinical Biomechanics 23 (2008) 662–720
repeated runs. The effects of creep were significantly less marked than with FSA. Differences between measured and applied average pressures ranged from 4% to 6.8% of the applied pressure with the Novel system, compared with a range of 18.4% to 20.2% with FSA. Readings of average pressure with the Novel system increased by up to 3.7% of the initial pressure reading over a period of 30 min compared with 20.9% with FSA. Differences between measured and applied peak pressures ranged from 4.3% to 68.8% of the applied pressure with the FSA system, compared with a range of 3.1– 31.2% with Novel. Averaged over the five runs and the 30-min test period, error in peak pressure for the FSA system was between 28.7% and 56.7% compared with a range of 8.6–18.7% for Novel. Conclusion The superior accuracy and repeatability of the Novel system indicate that it should be considered the pressure mapping device of choice in clinical and research settings. References Fuhrer, M.J., Garber, S.L., Rintala, D.H., Clearman, R., Hart, K.A., 1993. Pressure ulcers in community-resident persons with spinal cord injury: prevalence and risk factors. Archives of Physical Medicine and Rehabilitation 74 (11), 1172–1177. O’Connor, K., 2005. Pressure ulcers. In: DeLisa, J.A., et al. (Eds.), Physical Medicine and Rehabilitation: Principles and Practice, Lippincott Williams & Wilkins 4th ed., vol. 2. pp. 1605–1618.
rider and the horse. For measurements, the pressure measuring pad (Pliance System, Novel) was used directly on the horse’s back. We measured a group of five healthy subjects without earlier riding experience (in a healthy subject we assume normal motor abilities, without the bias of any health deficiency) at the first and the sixth sessions of hippotherapy at the walk. In each session the physiotherapist assisted from behind and corrected the posture of each subject. Results The cycle of pressure distribution in hippotherapy has similar characteristics as the pressures occurring during athletic horse riding. In the first measurement the range of total power is between 568 and 406 N, the maximal pressure varies from 1.31 to 1.84 N m 2 and minimum from 0.38 to 0.44 N m 2. Six hippotherapy sessions later, the results of the second measurement were in the range of total power between 639 and 453 N, the maximal pressure varied from 1.59 to 2.1 N m 2 and minimum from 0.41 to 0.49 N m 2. Discussion The effect of six sessions of training was an increase in forces on the horse’s back, which we assume is due to the increased contact between horse and rider as the excitement and stress of the new situation and movement activity recedes.
doi:10.1016/j.clinbiomech.2008.03.010 doi:10.1016/j.clinbiomech.2008.03.011
Pressure forces created by the contact of a rider’s body on the horse’s back during hippotherapy T. Dvorakova a, Ch Peham b, M. Janura a,b a
Palacky University Olomouc, Department of Biomechanics and Engineering Cybernetics, Faculty of Physical Culture, Czech Republic b University of Veterinary Medicine Vienna, Clinic of Orthopaedics in Ungulates, Austria Introduction One of the most important tasks of a therapist practicing hippotherapy is to induce ‘‘a movement dialogue” between the horse and the client. It takes some time until the client adapts to the movement of the horse. The appropriate movement pattern of the client is built over time. As soon as this happens, we can say that the therapy has a neuro-physiological effect. Aims and method Our study describes how the increasing experience of the rider changes the cyclic pressure distribution between the
Reliability of PressurestatTM for measuring plantar foot pressures in patients with rheumatoid arthritis Jill Firth a, Deborah E. Turner b, Wendy Smith b, Philip S. Helliwell c, Jim Woodburn d a
School of Health Care Studies, University of Leeds, Leeds, United Kingdom b Department of Podiatry, University of Huddersfield, Huddersfield, United Kingdom c Academic Unit of Musculoskeletal Disease, University of Leeds, Leeds, United Kingdom d HealthQWest, Glasgow Caledonian University, Glasgow, Scotland, United Kingdom
Introduction Plantar pressure measurement (PPM) is used to assess foot function and as a screening tool to establish risk for tissue injury in the ‘at risk’ foot. The routine use of PPM is yet to be fully realized and one barrier may be the perceived reliance on costly specialist equipment. More recently, several semi-quantitative PPM systems have been