Monitoring in-shoe plantar pressures, temperature, and humidity: reliability and validity of measures from a portable device.

OBJECTIVE To investigate the reliability and validity of measures obtained from a portable electronic device used to monitor changes in plantar pressure, temperature, and humidity that occur within the shoe during prolonged activity. DESIGN Descriptive study comparing electronic sensor output with criterion values. SETTINGS Indoor level walkway for pressure data; uncontrolled, outdoor environment for step count data; enclosed environmental control chamber for humidity and temperature data. PARTICIPANTS Convenience sample of 4 healthy, sensate subjects. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Correlations between sensor output and criterion measures were determined for pressure and temperature data. The absolute differences between sensor output and criterion values of temperature, humidity, and step count were also determined. RESULTS Pressure measurements from electronic sensors correlated highly with criterion values (r > or =.82), both before and after prolonged use. Relative humidity sensor output were within 5% of hygrometer values. In-shoe temperature data correlated highly with criterion values (r > or =.99), and differed from known temperatures by.50 degrees +/-.84 degrees C and.96 degrees +/- 1.56 degrees C at the forefoot and heel, respectively. Electronic step counts recorded at the central forefoot were within 1 step of visual step counts. Pressure tracings obtained from the device during different weight-bearing activities revealed qualitatively distinct pressure patterns. CONCLUSION The device provides valid and reliable measures of in-shoe plantar pressures, temperature, and humidity during prolonged activity.

[1]  G. Harris,et al.  Foot pressure distribution during walking and shuffling. , 1991, Archives of physical medicine and rehabilitation.

[2]  P. Veltink,et al.  Validity and reliability of measurements obtained with an "activity monitor" in people with and without a transtibial amputation. , 1998, Physical therapy.

[3]  W J Tompkins,et al.  A portable insole plantar pressure measurement system. , 1992, Journal of rehabilitation research and development.

[4]  N. Bergstrom,et al.  A Conceptual Schema for the Study of the Etiology of Pressure Sores , 1987, Rehabilitation nursing : the official journal of the Association of Rehabilitation Nurses.

[5]  C. Pieper,et al.  The reliability, validity, and stability of a measure of physical activity in the elderly. , 1996, Archives of physical medicine and rehabilitation.

[6]  S. Lundeen,et al.  Plantar Pressures During Level Walking Compared with Other Ambulatory Activities , 1994, Foot & ankle international.

[7]  M. J. Muêller,et al.  Hip and ankle walking strategies: effect on peak plantar pressures and implications for neuropathic ulceration. , 1994, Archives of physical medicine and rehabilitation.

[8]  M. J. Muêller,et al.  Relationship of foot deformity to ulcer location in patients with diabetes mellitus. , 1990, Physical therapy.

[9]  M. Ellenberg,et al.  Diabetes mellitus: theory and practice , 1970 .

[10]  Graf Pm.  The EMED System of foot pressure analysis. , 1993 .

[11]  M. J. Muêller.  Use of an in-shoe pressure measurement system in the management of patients with neuropathic ulcers or metatarsalgia. , 1995, The Journal of orthopaedic and sports physical therapy.

[12]  P. Cavanagh,et al.  In-Shoe Plantar Pressures During Activities of Daily Living: Implications for Therapeutic Footwear Design , 1996, Foot & ankle international.

[13]  A. Veves,et al.  Role of Neuropathy and High Foot Pressures in Diabetic Foot Ulceration , 1998, Diabetes Care.

[14]  W. F. Todd,et al.  Contralateral limb during total contact casting. A dynamic pressure and thermometric analysis. , 1995, Journal of the American Podiatric Medical Association.

[15]  M. Koch,et al.  Plantardruckmessung im Konfektionsschuh mit der TEKSCAN Sensorfolie. In-shoe Plantar Measurement with TEKSCAN Sensor System , 1993 .

[16]  Roger Bartlett,et al.  Pressure distribution and perceived comfort in casual footwear , 1995 .

[17]  T. Kernozek,et al.  Reliability of an In-Shoe Pressure Measurement System During Treadmill Walking , 1996, Foot & ankle international.

[18]  A. Veves,et al.  The optical pedobarograph. , 1993, Clinics in podiatric medicine and surgery.

[19]  R M Stess,et al.  The Role of Dynamic Plantar Pressures in Diabetic Foot Ulcers , 1997, Diabetes Care.

[20]  M Koch.  [Measuring plantar pressure in conventional shoes with the TEKSCAN sensory system]. , 1993, Biomedizinische Technik. Biomedical engineering.

[21]  M J Mueller,et al.  Generalizability of in-shoe peak pressure measures using the F-scan system. , 1996, Clinical biomechanics.

[22]  P. Cavanagh,et al.  Biomechanical Aspects of Diabetic Foot Disease: Aetiology, Treatment, and Prevention , 1996, Diabetic medicine : a journal of the British Diabetic Association.

[23]  K A Athanasiou,et al.  Is there a critical level of plantar foot pressure to identify patients at risk for neuropathic foot ulceration? , 1998, The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons.

[24]  T P Schmalzried,et al.  Quantitative Assessment of Walking Activity after Total Hip or Knee Replacement* , 1998, The Journal of bone and joint surgery. American volume.

[25]  Z O Abu-Faraj,et al.  A Holter-type, microprocessor-based, rehabilitation instrument for acquisition and storage of plantar pressure data. , 1997, Journal of rehabilitation research and development.

[26]  Young Cr,et al.  The F-SCAN system of foot pressure analysis. , 1993 .

[27]  P Sinnock,et al.  The Epidemiology of Lower Extremity Amputations in Diabetic Individuals , 1983, Diabetes Care.

[28]  G F Harris,et al.  Sensate and insensate in-shoe plantar pressures. , 1993, Archives of physical medicine and rehabilitation.

[29]  D A Boone,et al.  Step activity monitor: long-term, continuous recording of ambulatory function. , 1999, Journal of rehabilitation research and development.