A longitudinal investigation into the functional and physical durability of insoles used for the preventive management of neuropathic diabetic feet.

BACKGROUND: Insoles are commonly used to assist in the prevention of diabetic neuropathic foot ulceration. Insole replacement is often triggered only when foot lesions deteriorate, an indicator that functional performance is comprised and patients are exposed to unnecessary ulcer risk. We investigated the durability of insoles used for ulcer prevention in neuropathic diabetic feet over 12 months. METHODS: Sixty neuropathic individuals with diabetes were provided with insoles and footwear. Insole durability over 12 months was evaluated using an in-shoe pressure measurement device and through repeated measurement of material depth at the first metatarsal head and the heel seat. Analysis of variance was performed to assess change across time (at issue, 6 months, and 12 months). RESULTS: Analyses were conducted using all available data (n = 43) and compliant data (n = 18). No significant difference was found in the reduction of mean peak pressure tested across time (P < .05). For both sites, significant differences in insole depth were identified between issue and 6 months and between issue and 12 months but not between 6 and 12 months (P < .05). Most insole compression occurred during the initial 6 months. CONCLUSIONS: Visual material compression does not seem to be a reliable indicator of insole usefulness. Frequency of insole replacement is best informed by a functional review of effect determined using an in-shoe pressure measurement system. These results suggest that insoles for diabetic neuropathic patients can be effective in maintaining peak pressure reduction for 12 months regardless of wear frequency.

Patients' Experience of therapeutic footwear whilst living at risk of neuropathic diabetic foot ulceration: an interpretative phenomenological analysis (IPA).

BACKGROUND: Previous work has found that people with diabetes do not wear their therapeutic footwear as directed, but the thinking behind this behaviour is unclear. Adherence to therapeutic footwear advice must improve in order to reduce foot ulceration and amputation risk in people with diabetes and neuropathy. Therefore this study aimed to explore the psychological influences and personal experiences behind the daily footwear selection of individuals with diabetes and neuropathy. METHODS: An interpretative phenomenological analysis (IPA) approach was used to explore the understanding and experience of therapeutic footwear use in people living at risk of diabetic neuropathic foot ulceration. This study benefited from the purposive selection of a small sample of four people and used in-depth semi structured interviews because it facilitated the deep and detailed examination of personal thoughts and feelings behind footwear selection. FINDINGS: Four overlapping themes that interact to regulate footwear choice emerged from the analyses: a) Self-perception dilemma; resolving the balance of risk experienced by people with diabetes and neuropathy day to day, between choosing to wear footwear to look and feel normal and choosing footwear to protect their feet from foot ulceration; b) Reflective adaption; The modification and individualisation of a set of values about footwear usage created in the minds of people with diabetes and neuropathy; c) Adherence response; The realignment of footwear choice with personal values, to reinforce the decision not to change behaviour or bring about increased footwear adherence, with or without appearance management; d) Reality appraisal; A here and now appraisal of the personal benefit of footwear choice on emotional and physical wellbeing, with additional consideration to the preservation of therapeutic footwear. CONCLUSION: For some people living at risk of diabetic neuropathic foot ulceration, the decision whether or not to wear therapeutic footwear is driven by the individual 'here and now', risks and benefits, of footwear choice on emotional and physical well-being for a given social context.

Does footwear affect balance?: the views and experiences of people with diabetes and neuropathy who have fallen.

BACKGROUND: Despite falls being a major concern for people living with somatosensory deficit, little is known about the perceived impact of footwear and footwear features on balance. Clinical relevance is increased given that therapeutic footwear is often provided to people with diabetes to reduce foot ulcer risk. This qualitative study aims to explore the experiences and views of people with diabetes and neuropathy who have recently fallen to understand whether footwear type is perceived to affect balance or contribute to falling. METHODS: Sixteen individuals (13 men and three women aged 44-83 years) were purposively sampled from a larger population of potential participants. Audio-recorded, in-depth, semistructured interviews were conducted in participant homes or at a place preferable to them. Once transcribed verbatim, the data were themed, charted, and interpreted using a framework approach. RESULTS: Although most participants did not believe that the footwear in which they fell contributed to their fall, most revealed how footwear choice influenced their balance confidence to undertake daily tasks. Most found their therapeutic footwear "difficult" to walk in, "heavy, or "slippery bottomed." Design recommendations for enhanced balance included a close fit with tight fastening, lightweight, substantial tread, and a firm, molded sole/insole. Complying with these recommendations, the hiking sandal was believed to be the most stable and safe shoe and was frequently worn as a walking aid to reduce fear of falling and boost confidence. CONCLUSIONS: People with diabetic neuropathy have disease-specific needs and concerns relating to how footwear affects balance. Engaging with patients to address those needs and concerns is likely to improve the feasibility and acceptability of therapeutic footwear to reduce foot ulcer risk and boost balance confidence.

Effect of a forefoot off-loading postoperative shoe on muscle activity, posture, and static balance.

BACKGROUND: We investigated whether a forefoot off-loading postoperative shoe (FOPS) alters standing posture, ankle muscle activity, and static postural sway and whether any effects are altered by wearing a shoe raise on the contralateral side. METHODS: Posture, ankle muscle activity, and postural sway were compared in 14 healthy participants wearing either a FOPS or a control shoe with or without a contralateral shoe raise. Participants were tested under different sensory and support surface conditions. Additionally, reductions in peak pressure under the forefoot while walking were assessed with and without a contralateral shoe raise to determine whether the FOPS continued to achieve its primary off-loading function. RESULTS: Compared with the control condition, wearing a FOPS moved the center of pressure posteriorly, increased tibialis anterior muscle activity, and reduced ankle plantarflexor activity. These changes decreased when a contralateral shoe raise was added. No difference in postural sway was found between footwear conditions. Forefoot peak pressure was always reduced when wearing the FOPS. CONCLUSIONS: The posterior shift in center of pressure toward and behind the ankle joint axis is believed to result in the increase in tibialis anterior muscle activity that now acts as the primary stabilizer around the ankle. Instability may, therefore, increase in patients with weak tibialis anterior muscles (eg, diabetic neuropathy) who need to wear offloading devices for ulcer management. We suggest that the addition of a contralateral shoe raise fitted with a FOPS may potentially be beneficial in maintaining stability while off-loading the forefoot in this patient group.

A comparison of customised and prefabricated insoles to reduce risk factors for neuropathic diabetic foot ulceration: a participant-blinded randomised controlled trial.

BACKGROUND: Neuropathic diabetic foot ulceration may be prevented if the mechanical stress transmitted to the plantar tissues is reduced. Insole therapy is one practical method commonly used to reduce plantar loads and ulceration risk. The type of insole best suited to achieve this is unknown. This trial compared custom-made functional insoles with prefabricated insoles to reduce risk factors for ulceration of neuropathic diabetic feet. METHOD: A participant-blinded randomised controlled trial recruited 119 neuropathic participants with diabetes who were randomly allocated to custom-made functional or prefabricated insoles. Data were collected at issue and six month follow-up using the F-scan in-shoe pressure measurement system. Primary outcomes were: peak pressure, forefoot pressure time integral, total contact area, forefoot rate of load, duration of load as a percentage of stance. Secondary outcomes were patient perceived foot health (Bristol Foot Score), quality of life (Audit of Diabetes Dependent Quality of Life). We also assessed cost of supply and fitting. Analysis was by intention-to-treat. RESULTS: There were no differences between insoles in peak pressure, or three of the other four kinetic measures. The custom-made functional insole was slightly more effective than the prefabricated insole in reducing forefoot pressure time integral at issue (27% vs. 22%), remained more effective at six month follow-up (30% vs. 24%, p=0.001), but was more expensive (UK £656 vs. £554, p<0.001). Full compliance (minimum wear 7 hours a day 7 days per week) was reported by 40% of participants and 76% of participants reported a minimum wear of 5 hours a day 5 days per week. There was no difference in patient perception between insoles. CONCLUSION: The custom-made insoles are more expensive than prefabricated insoles evaluated in this trial and no better in reducing peak pressure. We recommend that where clinically appropriate, the more cost effective prefabricated insole should be considered for use by patients with diabetes and neuropathy. TRIAL REGISTRATION: Clinical trials.gov (NCT00999635). Note: this trial was registered on completion.

Effect of extrinsic rearfoot post design on the lateral-to-medial position and velocity of the center of pressure.

Findings from investigations of the effects of external forefoot and rearfoot posts added to foot orthoses have been inconclusive. This study was undertaken to examine the effects of rearfoot post design on the lateral-to-medial position and velocity of the center-of-pressure path. Four identical pairs of neutral-cast polypropylene orthotic shells were constructed; three pairs had a rearfoot post of specified design added. The fourth pair, the control, did not have a post added. Stance period data were broken down into four functional phases, and the statistically significant differences between the experimental conditions were calculated and analyzed. The addition of a rearfoot post to an orthotic shell affects center-of-pressure lateral-to-medial position and velocity. Although the effect of the post designs seemed to provide reasonably predictable changes in center-of-pressure position, the effect on center-of-pressure velocity was variable and inconsistent. The effect of the orthotic post was dependent on design and phase of gait. The addition of a rearfoot post and, specifically, the design of the post can probably be used to alter the center-of-pressure position and velocity.

The relationship between navicular drop and first metatarsophalangeal joint motion.

This study was conducted to determine whether navicular drop, as a representative measure of foot pronation, was associated with first metatarsal joint motion in 24 healthy subjects aged 21 to 40 years. The magnitude of first metatarsophalangeal joint motion was identified using a custom-built weightbearing goniometer designed to measure maximal hallux dorsiflexion in stance. The weightbearing measure of navicular drop was recorded using an adapted digital caliper. Statistical analysis demonstrated a significant negative correlation (P < .05) between the two variables. Furthermore, simple regression analysis suggested that 33.2% of the variation in maximal hallux dorsiflexion could be explained by different navicular drop values.