Michael J. Mueller

Comprehensive Foot Examination and Risk Assessment A report of the Task Force of the Foot Care Interest Group of the American Diabetes Association, with endorsement by the American Association of Clinical Endocrinologists

It is now 10 years since the last technical review on preventative foot care was published (1), which was followed by an American Diabetes Association (ADA) position statement on preventive foot care in diabetes (2). Many studies have been published proposing a range of tests that might usefully identify patients at risk of foot ulceration, creating confusion among practitioners as to which screening tests should be adopted in clinical practice. A task force was therefore assembled by the ADA to address and concisely summarize recent literature in this area and then recommend what should be included in the comprehensive foot exam for adult patients with diabetes. The committee was cochaired by the immediate past and current chairs of the ADA Foot Care Interest Group (A.J.M.B. and D.G.A.), with other panel members representing primary care, orthopedic and vascular surgery, physical therapy, podiatric medicine and surgery, and the American Association of Clinical Endocrinologists. The lifetime risk of a person with diabetes developing a foot ulcer may be as high as 25%, whereas the annual incidence of foot ulcers is ∼2% (3–7). Up to 50% of older patients with type 2 diabetes have one or more risk factors for foot ulceration (3,6). A number of component causes, most importantly peripheral neuropathy, interact to complete the causal pathway to foot ulceration (1,3–5). A list of the principal contributory factors that might result in foot ulcer development is provided in Table 1. View this table: Table 1— Risk factors for foot ulcers The most common triad of causes that interact and ultimately result in ulceration has been identified as neuropathy, deformity, and trauma (5). As identification of those patients at risk of foot problems is the first step in preventing such complications, this report will focus on key components of the …

Effect of Achilles tendon lengthening on neuropathic plantar ulcers. A randomized clinical trial.

Background:Limited ankle dorsiflexion has been implicated as a contributing factor to plantar ulceration of the forefoot in diabetes mellitus. The purpose of this study was to compare outcomes for patients with diabetes mellitus and a neuropathic plantar ulcer treated with a total-contact cast with

Total Contact Casting in Treatment of Diabetic Plantar Ulcers: Controlled Clinical Trial

This study compared the treatment of total contact casting (TCC) with traditional dressing treatment (TDT) in the management of diabetic plantar ulcers. Forty patients with diabetes mellitus and a plantar ulcer but with nogross infection, osteomyelitis, or gangrene were randomly assigned to the TCC group (n = 21) or TDT group (n = 19). Age, sex, ratio of insulin-dependent diabetes mellitus to non-insulin-dependent diabetes mellitus, duration of diabetes mellitus, vascular status, size and duration of ulcer, and sensation were not significantly different between groups (P > .05). In the experimental group, TCC was applied on the initial visit, and subjects were instructed to limit ambulation to ∼33% of their usual activity. Subjects in the control group were prescribed dressing changes and accommodative footwear and were instructed to avoid bearing weight on the involved extremity. Ulcers were considered healed if they showed complete skin closure with no drainage. Ulcers were considered not healed if they showed no decrease in size by 6 wk or if infection developed that required hospitalization. In the TCC group, 19 of 21 ulcers healed in 42 ± 29 days; in the TDT group, 6 of 19 ulcers healed in 65 ± 29 days. Significantly more ulcers healed (χ2 = 12.4, P < .05) and fewer infections developed (χ2 = 4.1, P < .05) in the TCC group. We conclude TCC is a successful method of treating diabetic plantar ulcers but requires careful application, close follow-up, and patient compliance with scheduled appointments to minimize complications.

Excessive Adipose Tissue Infiltration in Skeletal Muscle in Individuals With Obesity, Diabetes Mellitus, and Peripheral Neuropathy: Association With Performance and Function

Background and Purpose: The primary purpose of this study was to report differences in calf intermuscular adipose tissue (IMAT), muscle strength (peak torque), power, and physical function in individuals with obesity, diabetes mellitus (DM), and peripheral neuropathy (PN) compared with those without these impairments. A secondary purpose was to assess the relationship between IMAT and muscle strength, power, and physical function. Subjects and Methods: Six participants with obesity, DM, and PN (2 women, 4 men; mean age=58 years, SD=10; mean body mass index=36.3, SD=5; mean modified Physical Performance Test [PPT] score=22, SD=3) and 6 age- and sex-matched control subjects without these impairments were assessed and compared in muscle strength, muscle power, physical functioning, and muscle and fat volume, including IMAT in the calf muscles. Muscle, adipose tissue, and IMAT volumes of each calf were quantified by noninvasive magnetic resonance imaging. Muscle strength and power of the plantar-flexor and dorsiflexor muscles were quantified using isokinetic dynamometry. The modified PPT was used to assess physical function. Results: Leg muscle and fat volumes were similar between groups, although IMAT volumes were 2.2-fold higher in the subjects with obesity, DM, and PN (X̄=120 cm3, SD=47) than in the control subjects (X̄=54 cm3, SD=41). Muscle strength, muscle power, ratio of leg muscle power to leg muscle volume, and modified PPT scores were lower in subjects with obesity, DM, and PN compared with the control subjects. Discussion and Conclusion: The data indicate that excess fat infiltration in leg skeletal muscles is associated with low calf muscle strength, low calf muscle power, and impaired physical function in individuals who are obese with DM and PN.

Navicular drop as a composite measure of excessive pronation

The measure of navicular drop has been used as an indicator of pronation at the foot. It is defined as the distance the navicular tuberosity moves in standing, as the subtalar joint is allowed to move from its neutral position to a relaxed position. The purposes of this study were to test the reliability of a method to measure navicular drop and to assess the relationships among measures of forefoot to rearfoot position, subtalar joint neutral position, and navicular drop. The results support traditional biomechanical theory but indicate that other factors contribute significantly to navicular drop.

Hip and ankle walking strategies : effect on peak plantar pressures and implications for neuropathic ulceration

Treatment of neuropathic plantar ulcers often is directed at reducing excessive, repeated peak plantar pressures (PPP). The purposes of this study were to determine whether instructing a subject to walk using a hip strategy would reduce forefoot PPP and change the kinematics of walking during a single session of testing. Thirteen subjects, 7 with peripheral neuropathy and a history of a recent plantar ulcer, and 6 controls participated. PPPs were measured with an in-shoe pressure monitoring system. Kinematics were measured with a computer-assisted motion analysis system. After data were collected as subjects walked using their normal walking pattern, subjects were instructed to walk using the hip strategy by decreasing their push-off, pulling their leg forward from their hips, decreasing step length, and maintaining their normal walking velocity. Compared with using the normal (ankle) strategy, using the hip strategy showed a significant 27% decrease in forefoot PPP and a 24% increase in heel PPP. Kinematic changes were decreased plantar flexion angular velocity, hip extension range-of motion (ROM), and step length, increased dorsiflexion ROM, and hip flexion ROM, but no change in walking velocity. These findings indicate that a change in walking pattern can result in lower forefoot PPP during a single session. Assuming patients can maintain the alterations in their walking pattern, these adaptations may help to heal plantar ulcers in some patients with peripheral neuropathy.

Comparison of muscle activity during walking in subjects with and without diabetic neuropathy

The purpose of this study was to compare muscle activity and joint moments in the lower extremities during walking between subjects with diabetic neuropathy (DN) and control subjects. Tests were performed on nine subjects with DN, and nine age, gender, and weight-matched controls. Onset and cessation times of lower extremity electromyographic (EMG) activity and joint moments were determined. Results demonstrated that subjects with DN had less ankle mobility, slower walking speeds, longer stance phases, and lower peak ankle dorsiflexion, ankle plantar flexion, and knee extension moments than control subjects. Onset times with respect to heel-strike (HS) for the soleus, medial gastrocnemius, and medial hamstring muscles were significantly earlier during the gait cycle (GC) in subjects with DN than in control subjects. The cessation times of soleus, tibialis anterior, vastus medialis, and medial hamstring muscles were significantly prolonged in subjects with DN. Subjects with DN showed more co-contractions of agonist and antagonist muscles at the ankle and knee joints during stance phase compared with control subjects. These gait changes and co-contractions may allow subjects with DN to adopt a safer, more stable gait pattern to compensate for diminished sensory information from the ankle and the foot. The premature activation of soleus and medial gastrocnemius muscles in subjects with DN could be contributing to abnormal forefoot plantar pressure distribution. Additional research is needed to clarify the relationship between the premature activation of triceps surae muscles and the forefoot plantar pressure parameters in subjects with DN.

Comparison of physical activity and cumulative plantar tissue stress among subjects with and without diabetes mellitus and a history of recurrent plantar ulcers

OBJECTIVES To compare the amount of weight-bearing activity and estimates of cumulative plantar tissue stress between subjects with and without diabetes mellitus and a history of recurrent plantar ulcers. DESIGN Cross-sectional study with matched groups. BACKGROUND Weight-bearing activity among individuals with diabetes is likely to influence the amount of mechanical trauma accumulated by plantar tissues, yet activity levels have not been accounted for in previous measurements of plantar tissue stress or predictions of plantar tissue injury. METHODS Study groups included subjects with diabetes mellitus and peripheral neuropathy, either with or without a history of recurrent plantar ulcers, and non-diabetic control subjects (n=10 per group). Pressure on the plantar foot was assessed as subjects walked at their preferred speed in the shoes they reported wearing most often each day. Physical activity was monitored over seven consecutive days using an accelerometer. The product of mean daily strides and forefoot pressure-time integral was used to estimate daily cumulative stress on the plantar forefoot. RESULTS Subjects with diabetes and a history of recurrent plantar ulcers were 46% less active than subjects without diabetes (mean (SD)=2727 (1345) versus 5037 (2624) strides/day, P=0.04), and accumulated 41% less daily stress on the forefoot than non-diabetic and diabetic control subjects without a history of plantar ulcers (mean (SD)= 210 (134) versus 354 (118) and 354 (148) MPas/day respectively, P=0.03). CONCLUSIONS Subjects with diabetes and a history a previous ulcers may be susceptible to plantar tissue injury even at relatively low levels of cumulative tissue stress. RELEVANCE Changes in weight-bearing activity following plantar tissue injury in patients with diabetes may influence plantar tissue adaptation and the risk of ulcer recurrence.

Effect of Weight-Bearing Activity on Foot Ulcer Incidence in People With Diabetic Peripheral Neuropathy: Feet First Randomized Controlled Trial

Background: Weight-bearing exercise has been contraindicated among people with diabetic peripheral neuropathy (DM+PN). However, recent cohort studies have suggested that daily weight-bearing activity is associated with lower risk for foot ulceration. Objective: The objective of this study was to determine the effect of a lower-extremity exercise and walking intervention program on weight-bearing activity and foot ulcer incidence in people with DM+PN. Design: This was an observer-blinded, 12-month randomized controlled trial. Setting: The settings were physical therapy offices in part 1 of the intervention and the community in part 2 of the intervention. Participants: The participants were 79 individuals with DM+PN who were randomly assigned either to a control group (n=38) or an intervention group (n=41) group. Intervention: Intervention components included leg strengthening and balance exercises; a graduated, self-monitored walking program (part 1); and motivational telephone calls every 2 weeks (part 2). Both groups received diabetic foot care education, regular foot care, and 8 sessions with a physical therapist. Measurements: Total and exercise bout–related daily steps at baseline and at 3, 6, and 12 months were measured by accelerometers. Foot lesions/ulcers were photographed and classified by an independent panel of dermatologists. Use of adequate footwear was monitored. Results: At 6 months, bout-related daily steps increased 14% from baseline in the intervention group and decreased 6% from baseline in the control group. Although the groups did not differ statistically in the change in total daily steps, at 12 months steps had decreased by 13% in the control group. Foot ulcer rates did not differ significantly between groups. Conclusion: Promoting weight-bearing activity did not lead to significant increases in foot ulcers. Weight-bearing activity can be considered following adequate assessment and counseling of patients with DM+PN.

Therapeutic Footwear Can Reduce Plantar Pressures in Patients With Diabetes and Transmetatarsal Amputation

OBJECTIVE To compare how footwear (full-length shoe or short shoe), a total contact insert, a rigid rocker-bottom (RRB) sole, and an ankle-foot orthosis (AFO) affect peak plantar pressure (PPP) on the distal residuum and contralateral extremity of patients with diabetes and transmetatarsal amputation (TMA). RESEARCH DESIGN AND METHODS Thirty patients with diabetes and TMA participated (mean age 62 ± 4 years). In-shoe plantar pressures during walking were measured in six types of footwear. Each measurement occurred after a 1-month adjustment period. Repeated measure analysis of variance (ANOVA) was used to compare treatments. RESULTS All five types of therapeutic footwear reduced plantar pressures compared with regular shoes with a toe-filler (P < 0.05). A full-length shoe, total contact insert, and RRB sole resulted in lower pressures on the distal residuum (222 vs. 284 kPa) and forefoot of the contralateral extremity (197 vs. 239 kPa), compared with a regular shoe and toe-filler. Footwear with an AFO showed reduced PPP on the residuum, but most patients complained of reduced ankle motion during walking. A short shoe reduced pressures on the residuum, but not on the contralateral extremity, and many patients had complaints regarding cosmesis of the shoe. CONCLUSIONS The full-length shoe, total contact insert, and an RRB sole provided the best pressure reduction for the residuum and contralateral foot, with the optimal compromise for cosmetic acceptance and function.