Ayumi Amemiya

Morphological pattern classification system for plantar thermography of patients with diabetes.

Background: A plantar temperature distribution can be obtained by thermography; however, the advantage has not been effectively utilized in the past. We previously proposed a classification method based on the angiosome concept, but the method was insufficient because it was too subjective and complicated for clinicians. In this study, we propose a new classification system of plantar forepart thermographic patterns using an image segmentation technique. Methods: A cross-sectional observational study was conducted including 32 healthy volunteers and 129 patients with diabetes mellitus (DM). Individual thermographic variations and trends were evaluated. A comparison was conducted between the patterns obtained by our previous angiosome-based research and the patterns found by the new classification system. Results: The system objectively found wider variations of the plantar forepart thermographic patterns in the patients with DM compared with those in the control subjects. In patients with DM, the system showed that the whole-high pattern was most frequent (46%), followed by the butterfly pattern (12%). In the control group, the butterfly pattern was most frequent (44%), followed by the whole-high pattern (19%). Both ankle and toe brachial indices were higher in feet with high temperature area in the inner side of the plantar. Conclusions: Thermographic patterns found by the new computer-based system were similar to those obtained in our previous subjective work. The classification system found forefoot-low pattern and tiptoe-low pattern objectively. The system based on infrared thermography will be a screening tool to assess circulatory status in daily foot care of patients with DM.

Elevated plantar pressure in diabetic patients and its relationship with their gait features

PURPOSE High plantar pressure is a major risk factor for diabetic foot ulcers. The relationship between plantar pressure and foot mobility has been investigated in some studies. However, when the foot is in motion, foot mobility is only a small feature of the gait. Therefore, we investigated relationship between high plantar pressure and gait and also studied the motion of the trunk. In addition, we investigated the relationship between gait and patient characteristics to identify patients at high-risk of developing diabetic foot ulcers. METHODS The relationships between elevated plantar pressure, gait features, and patient characteristics were analyzed. Plantar pressure distribution in the stance phase was divided on the four plantar segments. Elevated plantar pressure was defined as being more than the mean plus one standard deviation of the corresponding segment in non-diabetic subjects. Plantar pressure distribution was measured by an F-scan system, and gait features were measured using wireless motion sensors attached to the sacrum and feet. Patient characteristics were obtained from medical records or by interview. RESULTS Small roll and yaw motions of the body and yaw motion of the foot during the mid-stance phase were related to the elevated plantar pressure in 57 diabetic patients. Furthermore, these gait features were related to sensory neuropathy, diabetes duration, patient weight, toe-gap force, and ankle range of motion. CONCLUSION Given our findings, it may be possible to prevent diabetic foot ulcers by increasing foot motion during the mid-stance phase. Passive exercise aimed at expanding ankle range of motion in patients with sensory neuropathy or long-standing diabetes may assist in achieving this.

Shear Stress-Normal Stress (Pressure) Ratio Decides Forming Callus in Patients with Diabetic Neuropathy

Aim. Callus is a risk factor, leading to severe diabetic foot ulcer; thus, prevention of callus formation is important. However, normal stress (pressure) and shear stress associated with callus have not been clarified. Additionally, as new valuables, a shear stress-normal stress (pressure) ratio (SPR) was examined. The purpose was to clarify the external force associated with callus formation in patients with diabetic neuropathy. Methods. The external force of the 1st, 2nd, and 5th metatarsal head (MTH) as callus predilection regions was measured. The SPR was calculated by dividing shear stress by normal stress (pressure), concretely, peak values (SPR-p) and time integral values (SPR-i). The optimal cut-off point was determined. Results. Callus formation region of the 1st and 2nd MTH had high SPR-i rather than noncallus formation region. The cut-off value of the 1st MTH was 0.60 and the 2nd MTH was 0.50. For the 5th MTH, variables pertaining to the external forces could not be determined to be indicators of callus formation because of low accuracy. Conclusions. The callus formation cut-off values of the 1st and 2nd MTH were clarified. In the future, it will be necessary to confirm the effect of using appropriate footwear and gait training on lowering SPR-i.

Factors Associated With Callus in Patients with Diabetes, Focused on Plantar Shear Stress During Gait

Background: The aim of this study is to identify whether plantar shear stress in neuropathic patients with diabetes with callus is increased compared with those without callus. Method: The differences in foot deformity, limited joint mobility, repetitive stress of walking, and ill-fitting shoes between patients with callus and those without callus were also determined. Subjects were recruited from the Diabetic Foot Outpatient Clinic. A newly developed in-shoe measurement system, which has flexible and thin insoles, enabled measurement of both plantar pressure and shear stress simultaneously when subjects walked as usual on a 10 m walkway. Results: It was found that plantar shear stress adjusted for weight during the push-off phase was increased by 1.32 times in patients with callus compared with those without callus (mean ± SD: 0.0500 ± 0.0160 vs 0.0380 ± 0.0144, P = .031). Moreover, hallux valgus deformity, reduction in dorsiflexion of the ankle joint and increase in plantar flexion were showed in feet with callus. Increased plantar shear stress may be caused by gait change that patients having callus push off with the metatarsal head instead of the toe as a result of foot deformity and limited joint mobility. Conclusions: It was found that plantar shear stress adjusted for weight during the push-off phase was increased in patients with callus compared with those without callus by using the newly developed measurement system. These results suggest that reduction of plantar shear stress during the push-off phase can prevent callus formation in neuropathic patients with diabetes.

Screening for tinea unguium by thermography in older adults with subungual hyperkeratosis

The purpose of the present study was to assess the difference in foot temperature between tinea unguium‐positive older adults with subungual hyperkeratosis and tinea unguium‐negative older adults with subungual hyperkeratosis to develop a temperature‐based screening method for tinea unguium.

Relationship between elevated plantar pressure of toes and forefoot and gait features in diabetic patients

This cross-sectional observational study is to reveal what kind of gait feature is relevant to elevated segment and its plantar pressure for prevention of diabetic foot ulcers. In 57 diabetic patients, the relationship between elevated plantar pressure and gait features was analyzed. To conduct this investigation, a simultaneous measurement system of plantar pressure and gait features was constructed. Plantar pressure distribution was measured by F-scan with customized footwear, and gait features were mainly measured using wireless motion sensors attached to the sacrum and feet. Several gait features of small rolling during the mid-stance phase were relevant to the elevated plantar pressure.

Establishment of a measurement method for in-shoe pressure and shear stress in specific regions for diabetic ulcer prevention

Pressure and shear stress are the factors of diabetic foot ulcers and callus formation. However, in-shoe shear stress of callus measurement could not have been measured because of technical difficulties. The purpose of this study is to verify reliability and validity of the established measurement system for in-shoe pressure and shear stress. For reliability, coefficients of variation (CV) and intraclass correlation coefficients (ICC) were confirmed. For known-groups validity, callus and non-callus feet were compared. Mean CV was 9.7%. Mean ICC was 0.943. For validity test, mean peak pressure and shear stress of the six callus feet was significantly higher than that of the eighteen non-callus feet. The pressure and shear stress that causes callus and diabetic foot ulcer will be identified in diabetic neuropathy patients.

Examination of the Effect of Suitable Size of Shoes under the Second Metatarsal Head and Width of Shoes under the Fifth Metatarsal Head for the Prevention of Callus Formation in Healthy Young Women

Excessive pressure and shear stress while walking cause a risk of callus formation, which eventually causes foot ulcers in patients with diabetes mellitus. Callus under the second metatarsal head (MTH) has been associated with increased shear stress/pressure ratios (SPR). Callus under the fifth MTH has been associated with increased peak shear stress (PSS). The purpose of this study is to examine whether the effect of the suitable size and width of shoes prevents diabetic foot ulcers under the second and fifth MTH. We measured the pressure and shear stress by testing three kinds of sizes and two types of width of shoes. Significant difference was not observed in the SPR under the second MTH among different sizes of shoes. However, the pressure and shear stress were significantly lower when putting on shoes of fit size compared with larger sizes. The PSS under the fifth MTH was significantly smaller when putting on shoes of fit width compared with those of narrow width. Wearing shoes of fit size and width has the potential to prevent callus formation by reducing the pressure and shear stress constituting SPR under the second MTH and PSS under the fifth MTH.

The external force associated with callus formation under the first metatarsal head is reduced by wearing rocker sole shoes

Introduction: Callus is one of the main causes of diabetic foot ulcers. Therefore, preventing callus formation is very important. In a previous study, it was clarified that callus formation under the first metatarsal head (MTH) is associated with high shear stress time integral/pressure time integral (SPR-i). In another study, it was clarified that rocker sole shoes are effective in reducing peak pressure under the first MTH. Therefore, we hypothesized that rocker sole shoes reduce SPR-i under the first MTH. This study aimed to clarify the effect of rocker sole shoes for external forces and leg motions in comparison with that of the normal sole shoes.

The Association between Tinea Pedis and Feet-Washing Behavior in Patients with Diabetes: A Cross-sectional Study

OBJECTIVES: To examine the correlations between elements of feet-washing behavior, presence of tinea pedis (TP), and patients’ background characteristics in order to identify a concrete intervention method to prevent TP. DESIGN AND PARTICIPANTS: A cross-sectional study of 30 patients with diabetes (16 with TP) who were admitted to or visited the university hospital. MAIN OUTCOME MEASURES: The presence of TP was confirmed by the detection of dermatophytes by direct microscopy. Data on elements of feet-washing behavior, such as scrubbing between the toes, were collected by observing recorded videos of participants normally washing their feet as they do at home. The patients’ background characteristics included demographic data; diabetes-related factors; patient knowledge regarding diabetes, foot problems, and TP prevention; purpose for feet washing; and any difficulties in feet washing. MAIN RESULTS: The number of times patients scrubbed between their toes while washing with soap was significantly lower in patients with TP (odds ratio, 0.95; P = .036; with a cutoff value of 35 times) and those who had difficulty in reaching their feet with their hands (B = −14.42, P = .041). CONCLUSIONS: An effective foot-washing protocol should include specific instructions for patients to scrub between their toes at least 35 times in all 8 spaces while washing with soap. Appropriate advice is also needed for individuals who have difficulty reaching their feet with their hands. Education about appropriate foot-washing behavior may potentially prevent TP.