Diabetic foot biomechanics and gait dysfunction

Examination time-distance characteristics of gait and pelvic kinematics in individuals with Diabetic polyneuropathy: a case-control study

BACKGROUND

Diabetic Peripheral Neuropathy (DPN) disrupts body and movement biomechanics, increases mechanical stress during walking, and predisposes individuals to injuries owing to the repetitive effects of these stresses.

AIMS

This study aimed to assess and compare the impact of neuropathy on gait and pelvic kinematics in individuals with DPN.

METHODS

This case-control study included two groups: 23 individuals diagnosed with DPN aged between 35-70 and 23 healthy individuals aged-35-70. The BTS-G, a wireless motion sensor, was used to assess the time-distance characteristics of walking in all participants. The system analyzed data pertaining to walking speed, cadence, percentages of stance and swing phases, durations of walking cycles, double-step lengths, pelvic tilt, obliquity, and rotation symmetries.

RESULTS

There were no statistically significant differences between the groups in cadence, left and right stance phase percentages, or left and right swing phase percentages (p > 0.05). However, significant differences were observed between the groups in terms of speed, left and right walking cycle durations, and left and right double-step lengths (p < 0.05). Additionally, no statistically significant difference was found between the groups in pelvic tilt symmetry and left and right pelvic tilt range of motion values (p > 0.05). Nevertheless, significant differences were identified between the groups in pelvic obliquity symmetry, pelvic rotation symmetry, left and right pelvic obliquity range of motion, and left and right pelvic rotation range of motion values (p < 0.05).

CONCLUSIONS

The findings of this study suggest that individuals with DPN exhibit decreased walking speed, prolonged gait cycle duration, increased double step length, and reduced pelvic obliquity and rotation range of motion.

The effects of wearing textured versus smooth shoe insoles for 4-weeks in people with diabetic peripheral neuropathy: a randomised controlled trial

PURPOSE

To determine whether short-term wear of textured insoles alters balance, gait, foot sensation, physical activity, or patient-reported outcomes, in people with diabetic neuropathy.

MATERIALS AND METHODS

53 adults with diabetic neuropathy were randomised to wear textured or smooth insoles for 4-weeks. At baseline and post-intervention, balance (foam/firm surface; eyes open/closed) and walking were assessed whilst barefoot, wearing shoes only, and two insoles (textured/smooth). The primary outcome was center of pressure (CoP) total sway velocity. Secondary outcomes included other CoP measures, spatiotemporal gait measures, foot sensation, physical activity, and patient-reported outcomes (foot health, falls efficacy).

RESULTS

Wearing textured insoles led to improvements in CoP measures when standing on foam with eyes open, relative to smooth insoles (p ≤ 0.04). The intervention group demonstrated a 5% reduction in total sway velocity, indicative of greater balance. The intervention group also showed a 9-point improvement in self-perceived vigour (p = 0.03). Adjustments for multiple comparisons were not applied.

CONCLUSIONS

This study provides weak statistical evidence in favour of textured insoles. Wearing textured insoles may alter measures of balance, suggestive of greater stability, in people with diabetic neuropathy. Plantar stimulation, through textured insoles, may have the capacity to modulate the perception of foot pain, leading to improved well-being.IMPLICATIONS FOR REHABILITATIONShort-term wear of textured insoles can lead to improvements in centre of pressure sway measures when standing on a compliant supporting surface.Wearing textured insoles may have the capacity to help relieve foot pain leading to enhanced self-perceived vitality in people with diabetic peripheral neuropathy.

Electrospun membranes chelated by metal magnesium ions enhance pro-angiogenic activity and promote diabetic wound healing

Diabetic wounds, resulting from skin atrophy due to localized ischemia and hypoxia in diabetic patients, lead to chronic pathological inflammation and delayed healing. Using electrospinning technology, we developed magnesium ion-chelated nanofiber membranes to explore their efficacy in antibacterial, anti-inflammatory, and angiogenic applications for wound healing. These membranes are flexible and elastic, resembling native skin tissue, and possess good hydrophilicity for comfortable wound bed contact. The mechanical properties of nanofiber membranes are enhanced by the chelation of magnesium ions (Mg2+), which also facilitates a long-term slow release of Mg2+. The cytocompatibility of the nanofibrous membranes is influenced by their Mg2+ content: lower levels encourage the proliferation of fibroblasts, endothelial cells, and macrophages, while higher levels are inhibitory. In a diabetic rat model, magnesium ion-chelated nanofibrous membranes effectively reduced early wound inflammation and notably accelerated wound healing. This study highlights the potential of magnesium ion-chelated nanofiber membranes in treating diabetic wounds.

Improving Physical, Physiological, and Psychological Health Outcomes in Patients with Diabetic Foot Ulcers - State of the Art

Diabetic foot disease is a complex and challenging complication of diabetes mellitus, which imposes a significant burden of disease on patients, their carers, and the wider health systems. Recurrence rates are high, and current evidence indicates a high mortality associated with it. While management algorithms have primarily focused on the physical aspects of healing, there is increasing recognition of the critical role played by psychological and biomechanical factors in the development and resolution of diabetic foot disease. Therefore, in this paper, we aim to explore how diabetic foot outcomes can be improved by addressing not only the physical but also the psychological and biomechanical aspects that are integral to the development of this condition and its optimal resolution. We explore new technologies that allow for non-invasive objective assessment of the diabetic foot at risk, and we also explore the role of understanding biomechanics, which is essential to determining risk of foot disease, but also the potential for recurrence. In addition, we discuss the evidence linking depression and cognitive impairment to diabetic foot disease and offer our insight on the research direction required before implementing novel information into front-line clinics.

Does Lower-Limb Tendon Structure Influence Walking Gait?

BACKGROUND

Within the exploration of human gait, key focal points include the examination of functional rockers and the influential role of tendon behavior in the intricate stretch-shortening cycle. To date, the possible relationship between these two fundamental factors in the analysis of human gait has not been studied. Therefore, this study aimed to analyze the relationship between the morphology of the patellar and Achilles tendons and plantar fascia with respect to the duration of the rockers.

METHODS

Thirty-nine healthy men (age: 28.42 ± 6.97 years; height: 173 ± 7.17 cm; weight: 67.75 ± 9.43 kg) were included. Data of the rockers were recorded using a baropodometric platform while participants walked over a 10 m walkway at a comfortable velocity. Before the trials, the thickness and cross-sectional area were recorded for the patellar tendon, Achilles tendon and plantar fascia using ultrasound examination. The relationship between the morphology of the soft tissue and the duration of the rockers was determined using a pairwise mean comparison (t-test).

RESULTS

A significant difference was found for rocker 1 duration, where a longer duration was found in the group of subjects with thicker patellar tendons. Regarding the Achilles tendon and plantar fascia, no significant differences were observed in terms of tendon morphology. However, subjects with thicker Achilles tendons showed a longer duration of rocker 1.

CONCLUSIONS

The findings underscore a compelling association, revealing that an increased thickness of the patellar tendon significantly contributes to the extension of rocker 1 duration during walking in healthy adults.

A Review on Relationship Between Charcot Neuroarthropathy and Diabetic Patients

Charcot Neuroarthropathy (CN) is a complex and incapacitating disorder characterized by neuropathy, progressive deformity, and joint destruction. It is of substantial interest within the diabetic population as this ailment chiefly affects individuals with diabetes. The pathophysiology of CN is multidimensional, connecting peripheral neuropathy, repetitive trauma, and autonomic dysfunction. The review analyses the mechanisms directing the development of CN, emphasizing the influence of diabetes in individuals who lean toward this condition. Clinical presentation and diagnosis of CN in diabetic patients present unique challenges. Complex clinical features have also been discussed, including joint deformities, insidious onset, and painless swelling, which mimic other musculoskeletal conditions. The diagnostic approaches, involving clinical examination and radiological imaging, are analyzed for early and accurate diagnosis. Risk factors and epidemiology emphasize the prevalence of CN within the diabetic population and draw attention to common risk factors contributing to its development. Significant factors such as glycemic control, duration of the disease, and type of diabetes are important in estimating an individual's risk for CN. Complications, such as foot ulcers and amputations, provide an understanding of the severe outcome of this condition on patients' quality of life. Management approaches and treatment involving conservative and surgical approaches are reviewed in depth. A multidisciplinary approach to patient care is emphasized, given the complex nature of CN and the comorbidities existing in diabetic individuals. Prognosis and prevention comprise approaches for mitigating the risk of CN in diabetic patients, such as glycemic control, regular foot examinations, and patient education. This thorough review aims to outline the intricate relationship between CN and diabetes, offering an understanding of pathophysiology, clinical complexities, diagnostic nuances, treatment modalities, and prevention strategies.

Effect of joint limitation and balance control on gait changes in diabetic peripheral neuropathy

Aims

This study analyzed the gait patterns of diabetic peripheral neuropathy (DPN) patients and changes in the center of mass sway to prevent the formation and recurrence of foot ulcers.

Methods

Forty-two subjects were divided into the diabetes mellitus (DM), DPN, and diabetic foot ulcer (DFU) groups. We measured the range of motion (ROM) of the lower limb joints in the resting position and the center of mass sway in the standing position. Joint angles, ROM during walking, and distance factors were evaluated.

Results

In the DFU group, ROM limitation during walking was detected at the knee joint, and functional and ROM limitations were found at the ankle joint. The step length ratio and step width in the DFU group were significantly lower and higher than those in the DM group, respectively. The sway distances in the DFU group were greater than those in the DM and DPN groups.

Conclusions

Functional joint limitations and gait changes due to the decreased ability to maintain the center of gravity were observed in the DFU group. As DPN progressed, the patients' gait became small, wide, and shuffled. Thus, supporting joint movement during walking may help reduce the incidence and recurrence of foot ulcers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00647-9.

Biokinetic Evaluation of Hallux Valgus during Gait: A Systematic Review

BACKGROUND

Foot pathologies can affect the kinetic chain during gait, leading to altered loading at other joints that can lead to subsequent pathologies. Although hallux valgus is the most common foot disease, little has been discussed about the biokinetic effects of hallux valgus on the foot and lower limb. This systematic review evaluated the kinematic, kinetic, and pedobarographic changes of the hallux valgus foot compared to a healthy one.

METHODS

Several electronic databases were searched up to January 2022, including only cross-sectional studies with clearly defined isolated hallux valgus diseases and healthy groups. Two investigators independently rated studies for methodological quality using the NIH Study Quality Assessment Tool for cross-sectional studies. Kinetic data were extracted, including temporal data, kinematics of the foot joint, kinematics of the proximal lower limb, and pedobarography. We did meta-analyses tests with a random effects model using the metafor package in R.

RESULTS

Hallux valgus patients walk slower compared to a disease-free control group -0.16 m/s (95% CI -0.27, -0.05). Hallux valgus patients exhibited significantly reduced coronal plane motion of the hindfoot-shank during preswing 1.16 degrees (95% CI 0.31, 2.00). Hallux valgus patients generated less force in the hallux region 33.48 N (95% CI 8.62, 58.35) but similar peak pressures in the hallux compared to controls. Hallux valgus patients generated less peak pressure at the medial and lateral hindfoot as compared to controls: 8.28 kPa (95% CI 2.92, 13.64) and 8.54 kPa (95% CI 3.55, 13.52), respectively.

CONCLUSION

Although hallux valgus is a deformity of the forefoot, the kinematic changes due to the pathology are associated with significant changes in the range of motion at other joints, underscoring its importance in the kinetic chain. This is demonstrated again with the changes of peak pressure. Nevertheless, more high-quality studies are still needed to develop a fuller understanding of this pathology.

Device-measured physical activity behaviours, and physical function, in people with type 2 diabetes mellitus and peripheral artery disease: A cross-sectional study

AIM

To quantify differences in device-measured physical activity (PA) behaviours, and physical function (PF), in people with type 2 diabetes mellitus (T2DM) with and without peripheral artery disease (PAD).

MATERIALS AND METHODS

Participants from the Chronotype of Patients with T2DM and Effect on Glycaemic Control cross-sectional study wore accelerometers on their non-dominant wrist for up to 8-days to quantify: volume and intensity distribution of PA, time spent inactive, time in light PA, moderate-to-vigorous PA in at least 1-minute bouts (MVPA1min), and the average intensity achieved during the most active continuous 2, 5, 10, 30, and 60-minute periods of the 24-h day. PF was assessed using the short physical performance battery (SPPB), the Duke Activity Status Index (DASI), sit-to-stand repetitions in 60 s (STS-60); hand-grip strength was also assessed. Differences between subjects with and without PAD were estimated using regressions adjusted for possible confounders.

RESULTS

736 participants with T2DM (without diabetic foot ulcers) were included in the analysis, 689 had no PAD. People with T2DM and PAD undertake less PA (MVPA1min: -9.2 min [95 % CI: -15.3 to -3.0; p = 0.004]) (light intensity PA: -18.7 min [-36.4 to -1.0; p = 0.039]), spend more time inactive (49.2 min [12.1 to 86.2; p = 0.009]), and have reduced PF (SPPB score: -1.6 [-2.5 to -0.8; p = 0.001]) (DASI score: -14.8 [-19.8 to -9.8; p = 0.001]) (STS-60 repetitions: -7.1 [-10.5 to -3.8; p = 0.001]) compared to people without; some differences in PA were attenuated by confounders. Reduced intensity of activity for the most active continuous 2-30 min in the 24-h day, and reduced PF, persisted after accounting for confounders. There were no significant differences in hand-grip strength.

CONCLUSIONS

Findings from this cross-sectional study suggest that, the presence of PAD in T2DM may have been associated with lower PA levels and PF.

Objective assessment of mobility among adults with diabetes and end-stage renal disease using walking aid: A cross-sectional cohort study

BACKGROUND

This cross-sectional study aimed to compare physical activity levels, plantar sensation, and fear of falling between individuals with diabetes undergoing hemodialysis, with or without walking aids.

METHODS

Sixty-four participants were recruited, with 37 not using walking aids (age = 65.8 ± 0.7 years, 46% female) and 27 using walking aids (age = 69.2 ± 1.2 years, 63% female). Physical activity was measured using validated pendant sensors over two consecutive days. Concern for falling and plantar numbness were assessed using the Falls Efficacy Scale-International and vibration perception threshold test, respectively.

FINDINGS

Participants using walking aids exhibited a greater fear of falling (84% vs. 38%, p < 0.01) and fewer walking bouts (p < 0.01, d = 0.67) and stand-to-walk transitions (p < 0.01, d = 0.72) compared to those not using walking aids. The number of walking bouts was negatively correlated with concern for falling scores (ρ = -0.35, p = 0.034) and vibration perception threshold (R = -0.411, p = 0.012) among individuals not using walking aids. However, these correlations were not significant among those using the walking aid. There was no significant group difference in active behavior (walking + standing %) and sedentary behavior (sitting + lying %).

INTERPRETATION

Those undergoing hemodialysis often lead sedentary lives, with mobility affected by fear of falling and plantar numbness. Using walking aids can help, but it doesn't guarantee more walking. A combined psychosocial and physical therapy approach is key for managing fall concerns and improving mobility.

Pathological gait in partial foot amputation versus peripheral neuropathy

Partial foot amputation (PFA) is a common surgical loss of part of either the forefoot or mid-foot. It is usually the sequel to a cascade of physiological foot dysfunction such as peripheral neuropathy (PN). The gait compensation mechanisms associated with these foot disorders aren't well understood yet.

PURPOSE

The aim of the study was to evaluate pathological gait compensation mechanisms in PFA due to PN versus PN alone through a comprehensive gait analysis.

METHODS

Plantar pressure, GRF, load distribution, footprint length and area, foot progression angle, step length, percentage of double limb support, and stance time were measured on 53 participants assigned into two well-matched groups: (A) 25 subjects with healed unilateral PFA and (B) 28 subjects with PN without ulcer. The gait analysis was conducted at a self-preferred walking speed using the FREEMED baropodometric platform and FREESTEP software.

RESULTS

The PFA group showed a significant decrease in load over the remaining toes and metatarsal heads compared to the PN group (p = .001 and p = .003, respectively). Conversely, the PFA group showed a significant increase in load over the mid-foot and peak plantar pressure during mid-stance (p = .007 and p = .016, respectively). All other measured variables showed no significant difference between the two groups (p > .05).

CONCLUSION

Individuals with PFA and PN or PN alone tend to shift their body loads posteriorly and redistribute their loads to compensate for the insufficient support from the forefoot. The PFA group was worse than the PN group. Furthermore, the PFA may not be the primary cause of the altered gait but rather the underlying systemic disease. The PFA surgery only worsens the compensatory mechanism.

Smart Offloading Boot System for Remote Patient Monitoring: Toward Adherence Reinforcement and Proper Physical Activity Prescription for Diabetic Foot Ulcer Patients

BACKGROUND

A critical factor in healing diabetic foot ulcers is patient adherence to offloading devices. We tested a smart offloading boot (SmartBoot) combined with a smartwatch app and cloud dashboard to remotely monitor patient adherence and activity. In addition, the impact of SmartBoot on balance, gait, and user experience was investigated.

METHODS

Fourteen volunteers (31.6±8.7 years; 64% female) performed natural activities (eg, sitting, standing, walking) with and without the SmartBoot for approximately 30 minutes. All participants completed balance tests, 10-meter walking tests at slow, normal, and fast pace while wearing the SmartBoot, and a user experience questionnaire. The accuracy of real-time adherence reporting was assessed by comparing the SmartBoot and staff observation. Center of mass (COM) sway and step counts were measured using a validated wearable system.

RESULTS

Average sensitivity, specificity, and accuracy for adherence and non-adherence were 90.6%, 88.0%, and 89.3%, respectively. The COM sway area was significantly smaller with the SmartBoot than without the SmartBoot regardless of test condition. Step count error was 4.4% for slow waking, 36.2% for normal walking, 16.0% for fast walking. Most participants agreed that the SmartBoot is easy to use, relatively comfortable, nonintrusive, and innovative.

CONCLUSIONS

To our knowledge, this is the first smart offloading system that enables remote patient monitoring and real-time adherence and activity reporting. The SmartBoot enhanced balance performance, likely due to somatosensory feedback. Questionnaire results highlight SmartBoot's technical and clinical potential. Future studies warrant clinical validation of real-time non-adherence alerting to improve wound healing outcomes in people with diabetic foot ulcers.

Accuracy of Foot Pressure Measurement on Predicting the Development of Foot Ulcer in Patients with Diabetes: A Systematic Review and Meta-Analysis

OBJECTIVE

Areas of the foot with diabetic ulcers have been observed to have greater plantar pressures compared to non-ulcerated. Pressures play an essential role in the mechanism of lesion, and their reduction is effective in prevention. We conducted a systematic review to evaluate pedobarography as a predictive tool for ulcer development, since there is still no consensus on this aspect.

METHODS

We searched PUBMED (MedLine), EMBASE, Scopus, Web of Science, CINAHL and Scielo for cohort studies that measured plantar pressure at baseline and verified ulcer development on follow-up. Pooled effects of accuracy, sensitivity, specificity and relative risk were calculated using the inverse variance method. Risk of bias was assessed using the QUADAS-2 tool.

RESULTS

Three studies (n = 2000) had enough information on accuracy to be included into a meta-analysis, and 4 (n = 2651) were analyzed using qualitative methods. Pooled sensitivity and specificity were found to be 0.63 (Confidence Interval (CI) 0.58-0.68) and 0.42 (CI 0.27-0.58), respectively. Pooled relative risk was 1.95 (CI 1.09-3.51). Risk of bias was low to uncertain.

CONCLUSIONS

Pedobarography in itself appears to have low accuracy in evaluating risk of ulceration. Several methodological heterogeneities were found, and the most optimal cut-off value is yet to be determined.

Decoding foot deformity and joint-destruction pathways in diabetes: Emerging insights from in-vivo foot joint kinetic measures

BACKGROUND

A comprehensive insight into the effect of longstanding diabetes mellitus and neuropathy on foot joint kinetics during walking is lacking. Our goal was to assess the in-vivo kinetics of major foot joints in persons with diabetes.

METHODS

Three groups, matched for age, sex and walking speed were recruited in this study: 1) people with diabetic peripheral neuropathy, 2) people with diabetes without peripheral neuropathy, and 3) control subjects without diabetes. Participants were instrumented with retroreflective markers on both feet and lower limbs and underwent a barefoot gait analysis using a state-of-the-art multi-segment kinetic foot modelling approach in order to provide accurate joint loading measures at the ankle, midtarsal, tarso-metatarsal and hallux joints.

FINDINGS

The group with neuropathy showed reduced ankle peak plantarflexion angular velocity compared to the control group (P = 0.002). Both groups with diabetes showed a significantly reduced midtarsal peak plantarflexion angular velocity, peak power generation and positive work compared to the control group (p < 0.01). Groups showed significant differences with respect to the tarsometatarsal peak dorsiflexion (p = 0.006) and plantarflexion angular velocity (P < 0.05).

INTERPRETATION

This study shows that both diabetes groups have similar joint loading and power absorption capacity but seem to lose their power generation capacity especially at the midtarsal joint. This loss of power generation capacity and the resulting decreased net mechanical work of the foot potentially embodies a foot that poorly supplements the body's mechanical energy during push-off. This phenomenon may cause excessive tissue stresses that contribute to foot deformity and joint-destruction mechanisms.

Type 2 diabetes mellitus and obesity: The synergistic effects on human locomotor function

BACKGROUND

Diabetes Mellitus and obesity represent two chronic multifactorial conditions which may induce modifications in human motion strategy. Our study focused on gaining insight into biomechanical aspects of gait occurring in patients affected by both aforementioned pathologies.

METHODS

One hundred subjects were recruited and divided into four groups: 25 obese-diabetic patients with peripheral neuropathy; 25 obese non-diabetic patients; 25 non-obese diabetic patients with peripheral neuropathy; 25 healthy volunteers participated as a control group. Subjects performed 3-D Gait Analysis while walking barefoot at self-selected speed, performing three consecutive trials. A multivariate analysis of variance test was used to assess spatio-temporal and kinematic data difference in the four groups. Tukey's post-hoc adjustment was applied on multiple groups' comparison.

FINDINGS

Diabetic-obese subjects showed increased step width compared to controls, while step and stride length, and walking velocity were reduced. Interestingly, step width presented increased values even compared to diabetic patients. Kinematics data showed a significant reduction in ankle plantarflexion during the push-off phase of the gait cycle compared to controls, and to obese subjects. Furthermore, knee kinematics revealed a reduced peak flexion during the swing time of the gait cycle, compared to controls and diabetic subjects, which resulted in reduced knee dynamic excursion during normal walking compared to healthy subjects.

INTERPRETATION

Our data demonstrated that diabetic-obese subjects present gait features typical of both such pathologies. The specific impairment of ankle and knee joint kinematics provides evidence of a synergistic effect of Diabetes Mellitus type 2 and obesity on human ambulatory function.

Digital Biomarkers of Gait and Balance in Diabetic Foot, Measurable by Wearable Inertial Measurement Units: A Mini Review

People with diabetic foot frequently exhibit gait and balance dysfunction. Recent advances in wearable inertial measurement units (IMUs) enable to assess some of the gait and balance dysfunction associated with diabetic foot (i.e., digital biomarkers of gait and balance). However, there is no review to inform digital biomarkers of gait and balance dysfunction related to diabetic foot, measurable by wearable IMUs (e.g., what gait and balance parameters can wearable IMUs collect? Are the measurements repeatable?). Accordingly, we conducted a web-based, mini review using PubMed. Our search was limited to human subjects and English-written papers published in peer-reviewed journals. We identified 20 papers in this mini review. We found preliminary evidence of digital biomarkers of gait and balance dysfunction in people with diabetic foot, such as slow gait speed, large gait variability, unstable gait initiation, and large body sway. However, due to heterogeneities in included papers in terms of study design, movement tasks, and small sample size, more studies are recommended to confirm this preliminary evidence. Additionally, based on our mini review, we recommend establishing appropriate strategies to successfully incorporate wearable-based assessment into clinical practice for diabetic foot care.

Influence of Contoured Insoles with Different Materials on Kinematics and Kinetics Changes in Diabetic Elderly during Gait

BACKGROUND

Alterations in the lower limb kinematics and kinetics of diabetic patients have been reported in previous studies. Inappropriate choices of orthopedic insole materials, however, fail to prevent diabetic foot ulcers and modify abnormal gait. The aim of this study was to quantitatively compare the effects of contoured insoles with different materials on the kinematics of and kinetics changes in the diabetic elderly during gait.

METHODS

There were 21 diabetic patients who participated in this study. Three-dimensional (3D) experimental contoured insoles constructed of soft (i.e., Nora Lunalastik EVA and PORON^® Medical 4708) and rigid (i.e., Nora Lunalight A fresh and Pe-Lite) materials with Langer Biomechanics longitudinal PPT^® arch pads were adopted. An eight-camera motion capture system (VICON), two force plates, and an insole measurement system-Pedar^® with 99 sensors-were utilized to obtain the kinematics and kinetics data. The plug-in lower body gait model landmarks were used for dynamic data acquisition during gait. The corresponding data from five gait cycles were selected and calculated.

RESULTS

The range of motions (ROMs) of the ankle joint (p = 0.001) and knee joint (p = 0.044) were significantly influenced when the contoured insoles were worn in comparison to the barefoot condition. The joint moments of the lower limbs with maximum ankle plantarflexion during the loading response and maximum knee and hip flexions were significantly influenced by the use of contoured insoles with different materials in the diabetic elderly. The peak plantar pressure (PPP) of the forefoot (p < 0.001), midfoot (p = 0.009), and rearfoot (p < 0.001) was significantly offloaded by the contoured insoles during the stance phase, whilst the PPP of the rearfoot (p < 0.001) was significantly offloaded during the swing phase.

CONCLUSIONS

The contoured insoles, especially those constructed with soft materials, significantly offloaded the PPP during gait-hence accommodating certain abnormal gait patterns more effectively compared to going barefoot.

Factors Associated with the Local Increase of Skin Temperature, 'Hotspot,' of Callus in Diabetic Foot: A Cross-Sectional Study

BACKGROUND

Increased local skin temperature (hotspot) on a callus site as detected by thermography is a well-known precursor of diabetic foot ulcers. This study aimed to determine the factors associated with callus hotspots in order to predict the risk of callus hotspots and then provide information for specific interventions.

METHODS

In this cross-sectional study, 1,007 patients' data from a diabetic foot prevention clinic between April 2008 and March 2020 were used. Data regarding patients' characteristics, foot calluses, and callus hotspots were collected and analyzed. Callus and callus hotspot were confirmed from foot photos and thermographs, respectively. A callus hotspot was defined as a relative increase in temperature compared to the skin surrounding the callus on the thermograph. Plantar pressure was measured with a pressure distribution measurement system. A generalized linear mixed model was used to identify the factors associated with callus hotspots.

RESULTS

Among the 2,014 feet, 28.5% had calluses, and 18.5% of feet with calluses had callus hotspots. The factors associated with callus hotspots were number of calluses (Adjusted odds ratio (aOR): 1.540, P = .003), static forefoot peak plantar pressure (SFPPP) (aOR: 1.008, P = .001), and body mass index (aOR: 0.912, P = .029).

CONCLUSIONS

Patients with a higher SFPPP were more likely to have callus hotspots suggesting that SFPPP might contribute to callus inflammation. SFPPP has the potential to be a useful predictor of callus hotspots in people with diabetes and at the same time provide information for off-loading interventions to prevent callus hotspots.

Aerobic exercise-induced circulating extracellular vesicle combined decellularized dermal matrix hydrogel facilitates diabetic wound healing by promoting angiogenesis

Background: Insufficient blood supply results in unsatisfactory wound healing, especially for challenging wound repair such as diabetic wound defects. Regular exercise training brings a lot of benefits to cardiovascular fitness and metabolic health including attenuation of T2DM progression. Circulating extracellular vesicles (EVs) are postulated to carry a variety of signals involved in tissue crosstalk by their modified cargoes, representing novel mechanisms for the effects of exercise. Prominently, both acute and chronic aerobic exercise training can promote the release of exercise-induced cytokines and enhance the angiogenic function of circulating angiogenic cell–derived EVs.

Methods: We investigated the possible angiogenesis potential of aerobic exercise-induced circulating EVs (EXE-EVs) on diabetic wound healing. Circulating EVs were isolated from the plasma of rats subjected to 4 weeks of moderate aerobic exercise or sedentariness 24 h after the last training session. The therapeutic effect of circulating EVs was evaluated in vitro by proliferation, migration, and tube formation assays of human umbilical vein endothelial cells (HUVECs), as well as in vivo by quantification of angiogenesis and cutaneous wound healing in diabetic rats.

Results: The number of circulating EVs did not change significantly in exercised rats 24 h post-exercise in comparison with the sedentary rats. Nevertheless, EXE-EVs showed remarkable pro-angiogenic effect by augmenting proliferation, migration, and tube formation of HUVECs. Furthermore, the findings of animal experiments revealed that the EXE-EVs delivered by decellularized dermal matrix hydrogel (DDMH) could significantly promote the repair of skin defects through stimulating the regeneration of vascularized skin.

Discussion: The present study is the first attempt to demonstrate that aerobic exercise-induced circulating EVs could be utilized as a cell-free therapy to activate angiogenesis and promote diabetic wound healing. Our findings suggest that EXE-EVs may stand for a potential strategy for diabetic soft tissue wound repair.

Characteristics of Plantar Pressure Distribution in Diabetes with or without Diabetic Peripheral Neuropathy and Peripheral Arterial Disease

Background. Excessive plantar pressure leads to increased risk of diabetic foot ulcers. Diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD) have been considered to be associated with alterations in gait and plantar pressure in diabetic patients. However, few studies have differentiated the effects with each of them. Objective. To investigate the plantar pressure distribution in diabetic patients, with DPN and PAD as independent or combined factors. Methods. 112 subjects were recruited: 24 diabetic patients with both DPN and PAD (DPN-PAD group), 12 diabetic patients with DPN without PAD (DPN group), 10 diabetic patients with PAD without DPN (PAD group), 23 diabetic patients without DPN or PAD, and 43 nondiabetic healthy controls (HC group). The in-shoe plantar pressure during natural walking was measured. Differences in peak pressure, contact area, proportion of high pressure area (%HP), and anterior/posterior position of centre of pressure (COP) were analysed. Results. Compared with HC group, in DPN-PAD group and DPN group, the peak pressures in all three forefoot regions increased significantly; in PAD group, the peak pressure in lateral forefoot increased significantly. The contact area of midfoot in the DPN-PAD group decreased significantly. PAD group had larger HP% of lateral forefoot, DPN group had larger HP% of inner forefoot, and DPN-PAD group had larger HP% of total plantar area. There was a significant tendency of the anterior displacement of COP in the DPN-PAD group and DPN group. No significant differences were observed between the D group and HC group. Conclusion. DPN or PAD could affect the plantar pressure distribution in diabetic patients independently or synergistically, resulting in increased forefoot pressure and the area at risk of ulcers. DPN has a more pronounced effect on peak pressure than PAD. The synergistic effect of them could significantly reduce the plantar contact area of midfoot.

Feet/Footwear-Related Fall Risk Screening Tool for Older Adults: Development and Content Validation

Background and Purpose

Screening for feet- and footwear-related influences on fall risk is an important component of multifactorial fall risk screenings, yet few evidence-based tools are available for this purpose. We developed the Screening Tool for Feet/Footwear-Related Influences on Fall Risk to support interprofessional health care providers in their efforts to screen for feet/footwear-related influences on fall risk among community-dwelling older adults identified at risk for falling.

Materials and Methods

The study consisted of two phases. During Phase 1, results of a systematic review of lower-limb factors associated with balance and falls informed tool development. The tool's initial draft was evaluated by an external group of nine interprofessional content experts. After incorporating changes recommended by Phase 1 participants, Phase 2 was initiated. During Phase 2, eight new interprofessional experts (19.3 average years of experience) completed the three rounds of a modified Delphi study.

Results

Phase 1 experts recommended modifying eight items and rated the tool's clarity, appeal and clinical feasibility as 81.2/100, 79.1/100, and 76.1/100, respectively. Phase 2 participants suggested combining items with similar recommended actions, adding a question about orthoses, and increasing the specificity of nine items. The refinements resulted in a 20-item screening tool. Each item was approved by the Phase 2 participants with > 80% agreement after two rounds of consensus voting, reflecting the tool's high face and content validity.

Conclusion

The new screening tool has high face and content validity and supports identification of feet- and footwear-related influences on fall risk among community-dwelling older adults. The tool can be used by interprofessional healthcare providers completing a multifactorial fall risk screening on community-dwelling adults identified as being at risk for falling.

Existing predictive methods applied to gait analysis of patients with diabetes: study protocol for a systematic review

INTRODUCTION

Type 2 diabetes can lead to gait abnormalities, including a longer stance phase, shorter steps and improper foot pressure distribution. Quantitative data from objective methods for evaluating gait patterns are accurate and cost-effective. In addition, it can also help predictive methods to forecast complications and develop early strategies to guide treatments. To date, no research has systematically summarised the predictive methods used to assess type 2 diabetic gait. Therefore, this protocol aims to identify which predictive methods have been employed to assess the diabetic gait.

METHODS AND ANALYSIS

This protocol will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) statement. Electronic searches of articles from inception to January 2022 will be performed, from May 2021 to 31 January 2022, in the Web of Science, MEDLINE, Embase, IEEE Xplore Digital Library, Scopus, CINAHL, Google Scholar, APA PsycInfo, the Cochrane Library and in references of key articles and grey literature without language restrictions. We will include studies that examined the development and/or validation of predictive methods to assess type 2 diabetic gait in adults aged >18 years without amputations, use of assistive devices, ulcers or neuropathic pain. Two independent reviewers will screen the included studies and extract the data using a customised charting form. A third reviewer will resolve any disagreements. A narrative synthesis will be performed for the included studies. Risk of bias and quality of evidence will be assessed using the Prediction Model Risk of Bias Assessment Tool and the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis.

ETHICS AND DISSEMINATION

Ethical approval is not required because only available secondary published data will be analysed. The findings will be disseminated through peer-reviewed journals and/or presentations at relevant conferences and other media platforms.

PROSPERO REGISTRATION NUMBER

CDR42020199495.

Effectiveness of Lower-Extremity Electrical Stimulation to Improve Skin Perfusion

BACKGROUND

Although numerous studies suggest the benefit of electrical stimulation (E-Stim) therapy to accelerate wound healing, the underlying mechanism of action is still debated. In this pilot study, we examined the potential effectiveness of lower-extremity E-Stim therapy to improve tissue perfusion in patients with diabetic foot ulcers.

METHODS

Thirty-eight patients with diabetic foot ulcers underwent 60 min of active E-Stim therapy on acupuncture points above the level of the ankle joint using a bioelectric stimulation technology platform. Perfusion changes in response to E-Stim were assessed by measuring skin perfusion pressure (SPP) at baseline and during 30 and 60 min of therapy; retention was assessed 10 min after therapy. Tissue oxygen saturation (SatO2) was measured using a noninvasive near-infrared camera.

RESULTS

Skin perfusion pressure increased in response to E-Stim therapy (P = .02), with maximum improvement observed at 60 min (11%; P = .007) compared with baseline; SPP reduced 10 min after therapy but remained higher than baseline (9%; P = .1). Magnitude of improvement at 60 min was negatively correlated with baseline SPP values (r = -0.45; P = .01), suggesting that those with lower perfusion could benefit more from E-Stim therapy. Similar trends were observed for SatO2, with statistically significant improvement for a subsample (n = 16) with moderate-to-severe peripheral artery disease.

CONCLUSIONS

This study provides early results on the feasibility and effectiveness of E-Stim therapy to improve skin perfusion and SatO2. The magnitude of benefit is higher in those with poorer skin perfusion. Also, the effects of E-Stim could be washed out after stopping therapy, and regular daily application might be required for effective benefit in wound healing.

Charcot Reconstruction: Outcomes in Patients With and Without Diabetes

The objective of this study is to compare risk adjusted matched cohorts of Charcot neuroarthropathy patients who underwent osseous reconstruction with and without diabetes. The 2 groups were matched based on age, body mass index, hypertension, history of end-stage renal disease, and peripheral arterial disease. Bivariate analysis was performed for preoperative infection, location of Charcot breakdown, and post reconstruction outcomes, in patients with a minimum of 1 year follow-up period. Through bivariate analysis, presence of preoperative ulceration (p = .0499) was found to be statistically more likely in the patients with diabetes; whereas, delayed osseous union (p = .0050) and return to ambulation (p ≤ .0001) was statistically more likely in patients without diabetes. The nondiabetic Charcot patients were 17.6 folds more likely to return to ambulation (odds ratio [OR] 17.6 [95% confidence interval {CI} {3.5-87.6}]), and 16.4 folds more likely to have delayed union (OR 16.4 [95% CI {1.9-139.6)]). Subanalysis compared well-controlled diabetic and nondiabetic Charcot neuroarthropathy patients for same factors. Multivariate analysis, in the subanalysis, found return to ambulation was 15.1 times likely to occur in the nondiabetic CN cohort (OR 15.1 [95% CI 1.3-175.8]) compared to the well-controlled diabetic CN cohort.

Comparison of WIFi, University of Texas and Wagner Classification Systems as Major Amputation Predictors for Admitted Diabetic Foot Patients: A Prospective Cohort Study

Introduction:

Classifications systems are powerful tools that could reduce the length of hospital stay and economic burden. The Would, Ischemia, and Foot Infection (WIFi) classification system was created as a comprehensive system for predicting major amputation but is yet to be compared with other systems. Thus, the objective of this study is to compare the predictive abilities for major lower limb amputation of WIFi, Wagner and the University of Texas Classification Systems among diabetic foot patients admitted in a tertiary hospital through a prospective cohort design.

Materials and Methods:

Sixty-three diabetic foot patients admitted from June 15, 2019 to February 15, 2020. Methods included one-on-one interview for clinico-demographic data, physical examination to determine the classification. Patients were followed-up and outcomes were determined. Pearson Chi-square or Fisher’s Exact determined association between clinico-demographic data, the classifications, and outcomes. The receiver operating characteristic (ROC) curve determined predictive abilities of classification systems and paired analysis compared the curves. Area Under the Receiver Operating Characteristic Curve (AUC) values used to compare the prediction accuracy. Analysis was set at 95% CI.

Results:

Results showed hypertension, duration of diabetes, and ambulation status were significantly associated with major amputation. WIFi showed the highest AUC of 0.899 (p = 0.000). However, paired analysis showed AUC differences between WIFi, Wagner, and University of Texas classifications by grade were not significantly different from each other.

Conclusion:

The WIFi, Wagner, and University of Texas classification systems are good predictors of major amputation with WIFi as the most predictive.

Potential Applications of Nanomaterials and Technology for Diabetic Wound Healing

Diabetic wound shows delayed and incomplete healing processes, which in turn exposes patients to an environment with a high risk of infection. This article has summarized current developments of nanoparticles/hydrogels and nanotechnology used for promoting the wound healing process in either diabetic animal models or patients with diabetes mellitus. These nanoparticles/hydrogels promote diabetic wound healing by loading bioactive molecules (such as growth factors, genes, proteins/peptides, stem cells/exosomes, etc.) and non-bioactive substances (metal ions, oxygen, nitric oxide, etc.). Among them, smart hydrogels (a very promising method for loading many types of bioactive components) are currently favored by researchers. In addition, nanoparticles/hydrogels can be combined with some technology (including PTT, LBL self-assembly technique and 3D-printing technology) to treat diabetic wound repair. By reviewing the recent literatures, we also proposed new strategies for improving multifunctional treatment of diabetic wounds in the future.

Lower-Limb Factors Associated with Balance and Falls in Older Adults: A Systematic Review and Clinical Synthesis

BACKGROUND

Despite sufficient evidence to suggest that lower-limb-related factors may contribute to fall risk in older adults, lower-limb and footwear influences on fall risk have not been systematically summarized for readers and clinicians. The purpose of this study was to systematically review and synethesize the literature related to lower-limb, foot, and footwear factors that may increase the risk of falling among community-dwelling older adults.

METHODS

We searched PubMed, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Library, and AgeLine. To describe the trajectory toward increasing risk of falls, we examined those articles that linked age-related changes in the lower limb or footwear to prospective falls or linked them to evidenced-based fall risk factors, such as gait and balance impairment.

RESULTS

This systematic review consisted of 81 articles that met the review criteria, and the results reflect a narrative review of the appraised literature for eight pathways of lower-limb-related influences on fall risk in older adults. Six of the eight pathways support a direct link to fall risk. Two other pathways link to the intermediate factors but lack studies that provide evidence of a direct link.

CONCLUSIONS

This review provides strong guidance to advance understanding and assist with managing the link between lower-limb factors and falls in older adults. Due to the lack of literature in specific areas, some recommendations were based on observational studies and should be applied with caution until further research can be completed.

Leveraging smart technologies to improve the management of diabetic foot ulcers and extend ulcer-free days in remission

The prevalent and long neglected diabetic foot ulcer (DFU) and its related complications rank among the most debilitating and costly sequelae of diabetes. Management of the DFU is multifaceted and requires constant monitoring from patients, caregivers, and healthcare providers. The alarmingly high rates of recurrence of ulcerations in the diabetic foot requires a change in our approach to care and to the vernacular in the medical literature. Our efforts should be directed not only on healing of open wounds, but also on maximizing ulcer-free days for the patient in diabetic foot remission. The increasing development and use of technology within every aspect of our lives represents an opportunity for creative solutions to prevent or better manage this devastating condition. In particular, recent advances in wearable and mobile health technologies appear to show promise in measuring and modulating dangerous foot pressure and inflammation to extend remission and improve the quality of life for these most complex patients. This review article discusses how harnessing wearables and digital technologies may improve the management and optimize prevention of DFUs by identifying high-risk patients for triage and timely intervention, personalizing prescription of offloading, and improving adherence to protective footwear. While still in their infancy, we envisage a future network of skin-worn, jewellery-worn, and implantable sensors that, if allowed to effectively communicate with one another and the patient, could dramatically impact measuring, personalizing, and managing how we and the patients we serve move through our collective world.

The impact of diabetic foot ulcers and unilateral offloading footwear on gait in people with diabetes

BACKGROUND

Unilateral offloading footwear prescribed to patients with diabetic foot ulcers elevates one limb relative to the other, which may lead to limp and abnormal gait. This study investigated whether the unilateral foot ulcer and offloading combination negatively impacts gait function beyond diabetic peripheral neuropathy.

METHODS

Eighty-six participants were recruited in 3 groups: 12 with diabetic peripheral neuropathy and unilateral foot ulcers wearing offloading footwear (offloading group, age = 55.6 ± 9.5 years, BMI = 30.9 ± 4.5 kg/m²), 27 with diabetic peripheral neuropathy (neuropathy group, age = 64.3 ± 7.7 years, BMI = 30.9 ± 5.4 kg/m²), and 47 non-diabetic controls (non-diabetic group, age = 62.9 ± 16.1 years, BMI = 29.0 ± 6.0 kg/m²). Gait function was quantified during a habitual speed walking test using a validated wearable platform.

FINDINGS

The offloading group exhibited deteriorated gait function compared to the non-diabetic group (p < 0.005, Cohen's effect size d = 0.90-2.61). They also had decreased gait speed (p < 0.001, d = 1.79) and stride length (p < 0.001, d = 1.76), as well as increased gait cycle time (p < 0.001, d = 1.67) and limp (p < 0.050, d = 0.72-1.49) compared to the neuropathy group. The offloading group showed increased gait unsteadiness compared to the neuropathy group, but the difference did not reach statistical significance in our samples.

INTERPRETATION

This study demonstrated that while diabetic peripheral neuropathy deteriorates gait function, including increasing gait unsteadiness and limp, the diabetic foot ulcer and offloading combination magnifies the deterioration beyond diabetic peripheral neuropathy. These findings promote caution of the current standards of care for treating diabetic foot ulcers with offloading footwear. However, it is possible that a contralateral shoe lift may remedy deteriorated gait function and improve quality of life for unilateral offloading users.

The Biomechanics of Diabetes Mellitus and Limb Preservation

Biomechanical changes to the lower extremity in patients with diabetes mellitus are typically greatest with peripheral neuropathy, although peripheral arterial disease also impacts limb function. Changes to anatomic structures can impact daily function. These static changes, coupled with kinetic and kinematic changes of gait, lead to increased vertical and shear ground reactive forces, resulting in ulcerations. Unsteadiness secondary to diminished postural stability and increased sway increase fall risk. These clinical challenges and exacerbation of foot position and dynamic changes associated with limb salvage procedures, amputations, and prostheses are necessary and can impact daily function, independence, quality of life, and mortality.

Influence of Diabetic Distal Symmetric Polyneuropathy on the Performance of the Musculoskeletal System of Lower Leg and Foot

Introduction:

Complications on the lower extremities are a major cause of morbidity, disability, emotional and physical suffering in people with diabetes. Diabetic neuropathy (DN) is the most frequent complication of both types of diabetes. Lack of performance of the musculoskeletal system of lower leg and foot can results in high focal plantar pressures with increased ulceration risk in patients with neuropathy.

Aim:

To determine the impact of the severity of distal symmetric polyneuropathy (DSPN) on the foot and ankle muscle strength and the range of motion (ROM) at ankle joint (AJ), subtalar joint (SJ) and first metatarsophalangeal joint (I MTP).

Methods:

A cross-sectional study was conducted among 100 diabetic patients. The level of DSPN was assessed using the Neuropathy Disability Score. Function of ten foot and ankle muscles has been evaluated by manual muscle testing. Muscle strength was scored by semiquantitative grading system used in the Michigan Diabetic Neuropathy Score. ROM at the AJ, SJ and I MTP was measured with goniometer.

Results:

The average patients age was 61.91±10.74 and diabetes duration 12.25±8.60 years. DSPN was present in 45% of patients. The average strength of foot and ankle muscles expressed by muscle score was 11.56±5.08. The average ROM at AJ was 47.85°, at SJ 35.10° and at I MTP 72.70°. Correlations between the severity of the DSPN and muscle function, ROM at AJ, SJ and I MTP were statistically significant. ROM at SJ and I MTP declines significantly with progression of neuropathy but not significant at AJ.

Conclusion:

The severity of DSPN is significantly associated with foot and ankle muscle weakness and ROM at the SJ and the I MTP, but not significantly with the ROM at the AJ.

The Effect of Daily Use of Plantar Mechanical Stimulation Through Micro-Mobile Foot Compression Device Installed in Shoe Insoles on Vibration Perception, Gait, and Balance in People With Diabetic Peripheral Neuropathy

OBJECTIVE

People with diabetic peripheral neuropathy (DPN) have impaired gait and balance performance. The aim of this study is to investigate therapeutic effectiveness of mechanical stimulation through a wearable foot compression device equipped in a shoe insole on vibration perception, balance control and gait performance in people with DPN.

METHODS

Using a single-arm 4-week intervention study design, we examined effectiveness of daily use of shoes equipped with the foot compression device (Footbeat™, AVEX, Grand Junction, CO, USA) on improving vibration perception threshold (VPT_max), skin perfusion pressure (SPP), ankle brachial index (ABI), lower extremities edema (circumferences in the calf and ankle), and motor performance (postural sway with eyes open and closed conditions, and gait performance during normal, dual-task and fast walking). Thirty people with type 2 diabetes and symptoms of PN completed the experimental protocol.

RESULTS

Improvements in VPT_max (before = 27.4 V, after = 23.3 V, P = .007, d = 0.33, where d denotes effect size), center-of-mass sway in the mediolateral direction with both eyes open and closed conditions (before = 0.94 cm, after = 0.76 cm, P = .020, d = 0.47; before = 1.10 cm, after = 0.83 cm, P = .033, d = 0.66, respectively), and stride velocity for normal walking, dual-task walking and fast walking tasks (before = 0.87 m/s, after = 0.96 m/s, P = .017, d = 0.41; before = 0.75 m/s, after = 0.91 m/s, P = .001, d = 0.77; before = 1.10 m/s, after = 1.20 m/s, P = .043, d = 0.33, respectively) were found post treatment. There was no significant improvement in SPP, ABI, and circumferences in the calf and ankle.

CONCLUSIONS

Our findings suggest the wearable foot compression device may be effective for reducing neuropathic symptoms and enhancing motor performances in people with DPN.

Measuring Plantar Tissue Stress in People With Diabetic Peripheral Neuropathy: A Critical Concept in Diabetic Foot Management

Excessive stress on plantar tissue over time is one of the leading causes of diabetic foot ulcers among people with diabetic peripheral neuropathy. Plantar tissue stress (PTS) is a concept that attempts to integrate several well-known mechanical factors into one measure, including plantar pressure, shear stress, daily weight-bearing activity, and time spent in prescribed offloading interventions (adherence). Despite international diabetic foot guidelines recommending the measure of each of these individual mechanical factors in people with neuropathy, only recently has technology enabled their combined measurement to determine PTS. In this article we review the concept of PTS, the mechanical factors involved, and the findings of pivotal articles reporting measures of PTS in people with neuropathy. We also discuss key existing gaps in this field, including the lack of standards to measure and report PTS, a lack of practical solutions to measure shear stress, and the lack of PTS thresholds that may indicate benefit or detriment to people with neuropathy. To address some of these gaps, we propose recommended clinical and research standards for measuring and reporting PTS in people with neuropathy. Last, we forecast future clinical, research, and technological advancements that may use PTS to highlight the importance of this critical concept in the prevention and management of diabetic foot ulcers.

Within- and Between-Body-Site Agreement of Skin Autofluorescence Measurements in People With and Without Diabetes-Related Foot Disease

BACKGROUND

Skin autofluorescence has been used to assess longer term glycemic control and risk of complications. There is however no agreed site at which autofluorescence should be measured. This study evaluated the within- and between-site agreement in measurement of skin autofluorescence using a noninvasive advanced glycation end product (AGE) reader.

METHODS

Overall, 132 participants were included: 16 with diabetes-related foot ulcers (DFU), 63 with diabetes but without foot ulcers (DMC), 53 without diabetes or foot ulcers (HC). Skin autofluorescence was measured using the AGE Reader (DiagnOptics technologies BV, the Netherlands). Three consecutive skin autofluorescence measurements were each performed at six different body sites: the volar surfaces of both forearms (arms), dorsal surfaces of both calves (legs), and plantar surfaces of both feet (feet). Within- and between-site agreements were analyzed with concordance correlation coefficients (CCC) and 95% confidence intervals (95% CI), absolute mean differences (±standard deviation), and Bland-Altman limits of agreement.

RESULTS

The agreement between repeat assessments at the same site was almost perfect (CCC [95% CI] ranging from 0.94 [0.91-0.96] for assessments in the right foot to 0.99 [0.99-0.99] for assessments in the left arm). The limits of agreement were narrow within ±0.5 arbitrary units for all sites. The between-site agreement in measurements was poor (CCC < 0.65) with large maximum absolute mean differences (±SD) in arbitrary units (DFU = 3.40 [±2.04]; DMC = 3.15 [±2.45]; HC = 2.72 [±1.83]) and wide limits of agreement.

CONCLUSIONS

Skin autofluorescence measurements can be repeated at the same site with adequate repeatability but measurements at different sites in the same patient have marked differences. The reason for this variation across sites and whether this has any role in diabetes-related complications needs further investigation.

An Innovative Application of the Free Vascularized Medial Femoral Condyle Flap in the Prevention of Recurring Neuropathic Ulcer in the Diabetic Foot: A Case Report

Despite various therapy options, the prophylactic and symptomatic treatment of recurrent ulcerations in the diabetic foot are still challenging. We report the application of a free vascularized medial femoral condyle flap to prevent the recurrence of pressure ulcer in a patient with diabetic foot syndrome. Our patient had type 2 diabetes and presented with pressure ulcers and osteomyelitis of metatarsal heads 2 and 3 after a great toe amputation. We chose to use a medial femoral condyle flap as a damper in the area of the metatarsal heads because of the relatively young age and good vascularity of our patient. We shaped the graft like a ski to distribute the pressure and prevent perforation of the plantar skin. Good results were achieved for wound healing, pain reduction, and improvement of gait. No pressure ulceration had recurred after a 3-year follow-up period. The versatility of the osteomyocutaneous graft from the medial femoral condyle is an important reconstructive tool for addressing major surgical problems. We present the first use of a medial femoral condyle flap in the treatment of a pressure ulcer in a diabetic foot. In selected patients, our method could prevent premature and extended amputations, thereby providing good improvement in patients' quality of life.

Using wearables to screen motor performance deterioration because of cancer and chemotherapy-induced peripheral neuropathy (CIPN) in adults - Toward an early diagnosis of CIPN

OBJECTIVE

An essential component for optimizing quality of life in adults with cancer is determining the degree to which therapy may negatively impact motor-performance, so that patients can maintain their quality of life and independence. This study examined whether instrumented gait and balance could determine the magnitude of deterioration in motor-performance from chemotherapy-induced peripheral neuropathy (CIPN).

METHODS

We recruited 84 adults with cancer (age = 71.1 ± 9.7 years old, BMI = 26.8 ± 6.2 kg/m², gender = 56%female) and 57 age-matched non-cancer patients (age = 69.5 ± 9.8 years old, BMI = 27.1 ± 6.0 kg/m², gender = 79%female). Based on clinical screening, the group with cancer was classified into two groups: participants with CIPN (CIPN+) and without CIPN (CIPN-). Gait and balance were quantified using validated wearables. The Vibration Perception Threshold (VPT) test was used to stratify the CIPN+ group into mild (Mild-CIPN) and severe (Severe-CIPN) subgroups.

RESULTS

All gait and balance parameters were deteriorated in the group with cancer compared to non-cancer group with the largest effects observed for stride-time (11%, Cohen's effect size d = 1.00, p < 0.001) and eyes-closed ankle sway (94%, d = 0.49, p = 0.001). The same trend was observed when the Severe-CIPN subgroup was compared to the Mild-CIPN. VPT correlates significantly with motor deterioration, with the largest correlation found in stride-time (Rho = 0.37, p = 0.007). Severe-CIPN subjects were significantly older and overall had more deterioration in the majority of motor-performance parameters after adjusting for age (p < 0.050).

CONCLUSION

These results confirmed the negative impact of CIPN on motor-performance with the largest effects on ankle stability and stride-time. VPT is a predictor of motor deterioration and may be used to determine the severity of CIPN symptom.

Distribution of the Highest Plantar Pressure Regions in Patients with Diabetes and Its Association with Peripheral Neuropathy, Gender, Age, and BMI: One Centre Study

The abnormal plantar pressure distribution and value play a key role in the formation of plantar calluses and diabetic foot ulcer. The prevalence of the highest pressure different distribution and its association with various factors among patients with diabetes is not well known. The study purpose was to evaluate the prevalence of different regions for the highest pressure on the sole and its association with selected factors among patients with diabetes. Medical records of nonulcer patients were retrospectively analysed. The relationship between pressure patterns on the sole obtained during a pedobarographic test as a semiquantitative assessment with colourful print analysis and neuropathy, gender, age, and BMI was searched. The most common location of the highest pressure was the central part of the forefoot. No association was found between the different highest pressure regions and age, sensory neuropathy, calluses, and foot deformities. The highest pressure on the lateral part of the foot and midfoot was observed more often in females and in patients with a BMI ≥ 35. The prevalence of the highest pressure on the forefoot was more common in patients with a BMI < 35. Conclusions. The most frequent regions of the highest pressure on the sole in patients with diabetes were the central part of the forefoot (2-3 metatarsal heads) with no simple relationship to the assessed variables other than BMI < 35. Female gender and higher BMI seem to be responsible for shifting the place of the highest pressure to other places of the foot.

Diabetic Gait Is Not Just Slow Gait: Gait Compensations in Diabetic Neuropathy

BACKGROUND

Neuropathic complications from diabetes mellitus affect multiple nerve types and may manifest in gait. However, gait compensations are still poorly understood, as narrow analyses and lack of speed controls have contributed to conflicting or equivocal results.

PURPOSE

To evaluate gait mechanics and energetics in diabetic peripheral polyneuropathy.

METHODS

Instrumented gait analysis was performed on 14 participants with diabetic peripheral polyneuropathy and 14 matched controls, walking at 1.0 m/s. A full-body model with a multisegment foot was used to calculate inverse dynamics and analyze sagittal plane metrics and time series waveforms across stance phase.

RESULTS

Alterations included increased hip and knee flexion in early stance followed by a prolonged hip extension moment in midstance. Late stance ankle dorsiflexion and power absorption were increased, and final push-off was delayed and truncated.

CONCLUSION

A neuropathic diabetic gait shares important similarities to a mild crouch gait with weakness/dysfunction in the foot and ankle. This study highlights two main compensation mechanisms that have been overlooked in previous literature. First, increased triceps surae stretch in terminal stance may be used to increase proprioception and/or energy storage, while a prolonged hip extension moment in midstance compensates for a limited push-off. These result in an overall workload shift from distal to proximal joints. Clinical assessment, monitoring, and treatment of neuropathy may benefit by focusing on these specific functional alterations.

Novel insole design for diabetic foot ulcer management

Around the world, over 400 million people suffer from diabetes. In a chronic diabetic condition, the skin underneath the foot often becomes extremely soft and brittle, resulting in the development of foot ulcers. In literature, a plethora of footwear designs have been developed to reduce the induced stresses on a diabetic foot and to consequently prevent the incidences of foot ulcers. However, to date, no insole design exists which can handle post-ulcer diabetic foot conditions without hindering the mobility of the patients. In the current work, a novel custom insole design with arch support and ulcer isolations was tested for effective stress reduction in a diabetic foot with ulcers using finite element modeling. A full-scale model of the foot was developed with ulcers of different geometries and sizes at the heel and metatarsal regions of the foot. The stresses at the ulcer locations were quantified for standing and walking with and without the novel custom insole model. The effect of material properties of the insole on the ulcer stress reduction was quantified extensively. Also, the effectivity of a novel synthetic skin material as the insole material was tested for stress offloading at the ulcers and the rest of the foot. From the analyses, peak stress reductions were observed at the ulcers up to 91.5% due to the ulcer isolation in the novel custom insole design and the skin-like material. Specifically, the ulcer isolation feature in the insole was found to be approximately 25% more effective in peak stress reduction for commonly occurring ulcers with irregular geometry, over the tested regular circular ulcer geometry. Also, a threshold material stiffness was found for the custom insole, below which the peak stresses at the ulcers did not decrease any further. Based on this information, a working prototype of the custom insole was developed with custom ulcer isolations, which will be subjected to further testing. The results of this study would inform better custom insole designing and material selection for post-ulcer diabetic conditions, with effective stress reduction at the ulcers, and the possibilities of preventing further ulceration.

Does First Ray Amputation in Diabetic Patients Influence Gait and Quality of Life?

It has recently been suggested that first ray amputation in diabetic patients with serious foot complications can prolong bipedal ambulatory status, and reduce morbidity and mortality. However, no data are available on gait analysis and quality of life after this procedure. In the present case-control study (6 amputee and 6 nonamputee diabetics, 6 healthy non-diabetic), a sample of amputee diabetic patients were evaluated and compared with a sample of nonamputee diabetic patients and a group of age-matched healthy subjects. Gait biomechanics, quality of life, and pain were evaluated. Compared with the other 2 groups, amputee patients displayed a lower walking speed and greater variability and lower ankle, knee, and hip range of motion values. They also tended to have a more flexed hip profile. Pain and lower quality of life were related to worsening biomechanical data. Our study results have shown that gait biomechanics in diabetic patients with first ray amputation are abnormal, probably owing to the severity of diabetes and the absence of the push-off phase provided by the hallux. Tailored orthotics and rehabilitation programs and a specific pain management program should be considered to improve the gait and quality of life of diabetic patients with first ray amputation.

Updates on Diabetic Foot and Charcot Osteopathic Arthropathy

PURPOSE OF REVIEW

Diabetes mellitus affects approximately 30.8 million people currently living in the USA. Chronic diabetes complications, including diabetic foot complications, remain prevalent and challenging to treat. We review clinical diagnosis and challenges providers may encounter when managing diabetic foot ulcers and Charcot neuroarthropathy.

RECENT FINDINGS

Mechanisms controlling these diseases are being elucidated and not fully understood. Offloading is paramount to heal and manage diabetic foot ulcers and Charcot neuroarthropathy. Diabetic foot ulcers recur and the importance of routine surveillance and multidisciplinary approach is essential. Several predictors of failure in Charcot foot include a related diabetic foot ulcer, midfoot or rearfoot location of the Charcot event, and progressive bony changes on interval radiographs. Patients with diabetic foot ulcer and/or Charcot neuroarthropathy are in need of consistent and regular special multidisciplinary care. If not diagnosed early and managed effectively, morbidity and mortality significantly increase.

Recent Advances and Future Opportunities to Address Challenges in Offloading Diabetic Feet: A Mini-Review

Diabetic foot ulcers (DFU) are a substantial dilemma for geriatric individuals with diabetes. The breakdown in tissue associated with DFU is typically a result of repetitive cycles of physical stress placed on the feet during weight-bearing activity. Accordingly, a key tenet in healing as well as preventing DFU is the use of offloading footwear to redistribute physical stress away from high stress locations such as bony prominences. Over the last several years there has been a substantial amount of effort directed at better understanding and implementing the practice of offloading. A review of this work as well as relevant technological advances is presented in this paper. Specifically, we will discuss the following topics in association with offloading diabetic feet: achieving optimal offloading, dosing activity/physical stress, thermal monitoring to detect preulcerative tissue damage, adherence with offloading devices, and optimizing the user experience. In addition to presenting progress to date, potential directions for further advancement are discussed.

Lower-extremity dynamics of walking in neuropathic diabetic patients who wear a forefoot-offloading shoe

BACKGROUND

A forefoot-offloading shoes has a negative-heel rocker outsole and is used to treat diabetic plantar forefoot ulcers, but its mechanisms of action and their association with offloading and gait stability are not sufficiently clear.

METHODS

Ten neuropathic diabetic patients were tested in a forefoot-offloading shoe and subsequently in a control shoe with no specific offloading construction, both worn on the right foot (control shoe on left), while walking at 1.2m/s. 3D-instrumented gait analysis and simultaneous in-shoe plantar pressure measurements were used to explain the shoe's offloading efficacy and to define centre-of-pressure profiles and left-to-right symmetry in ankle joint dynamics (0-1, 1:maximum symmetry), as indicators for gait stability.

FINDINGS

Compared to the control shoe, peak forefoot pressures, vertical ground reaction force, plantar flexion angle, and ankle joint moment, all in terminal stance, and the proximal-to-distal centre-of-pressure trajectory were significantly reduced in the forefoot-offloading shoe (P<0.01). Peak ankle joint power was 51% lower in the forefoot-offloading shoe compared to the control shoe: 1.61 (0.35) versus 3.30 (0.84) W/kg (mean (SD), P<0.001), and was significantly associated with forefoot peak pressure (R²=0.72, P<0.001). Left-to-right symmetry in the forefoot-offloading shoe was 0.39 for peak ankle joint power.

INTERPRETATION

By virtue to their negative-heel rocker-outsole design, forefoot-offloading shoes significantly alter a neuropathic diabetic patient's gait towards a reduced push-off power that explains the shoe's offloading efficacy. However, gait symmetry and stability are compromised, and may be factors in the low perceived walking discomfort and limited use of these shoes in clinical practice. Shoe modifications (e.g. less negative heel, a more cushioning insole) may resolve this trade-off between efficacy and usability.

Diabetic Neuropathy and Gait: A Review

Diabetic peripheral neuropathy (DPN) is a major sequela of diabetes mellitus and may have a detrimental effect on the gait of people with this complication. DPN causes a disruption in the body's sensorimotor system and is believed to affect up to 50% of patients with diabetes mellitus, dependent on the duration of diabetes. It has a major effect on morbidity and mortality. The peripheral nervous system controls the complex series of events in gait through somatic and autonomic functions, careful balancing of eccentric and concentric muscle contractions and a reliance on the sensory information received from the plantar surface. In this literature review focussing on kinetics, kinematics and posture during gait in DPN patients, we have identified an intimate link between DPN and abnormalities in gait and demonstrated an increased risk in falls for older patients with diabetes. As such, we have identified a need for further research on the role of gait abnormalities in the development of diabetic foot ulceration and subsequent amputations.

Gait alterations in the UAE population with and without diabetic complications using both traditional and entropy measures

Diabetic foot, one of the most common and debilitating manifestations of type 2 diabetes mellitus (T2DM), is the leading cause of worldwide non-traumatic lower extremity amputations. Diabetics who are at risk of ulceration are currently mainly identified by a thorough clinical examination of the feet, which typically does not show clear symptoms during the early stages of disease progression. In this study, we used a non-linear dynamics tool, gait entropy (GaitEN), in addition to traditional linear gait analysis methods, to investigate gait alterations amongst diabetic patients with combinations of three types of T2DM related complications: retinopathy, diabetic peripheral neuropathy (DPN) and nephropathy. Peak plantar pressure (PPP) was not significantly different in the group with DPN as compared to the control group (diabetics with no complications, CONT) in the forefoot region (DPN: mean±SD: 396±69.4kPa, CONT: 409±68.9kPa), although it was significantly lower in the heel region (DPN: mean±SD: 285±43.1.4kPa, CONT: 295±61.8kPa). On the other hand, gait entropy was significantly lower for the DPN compared to CONT group (DPN: 0.95±0.34, CONT: 1.03±0.28, p<0.05). The significant low entropy was maintained when neuropathy was combined with either retinopathy or nephropathy. For the group with all three complications (ALL-C), the entropy was higher than CONT (ALL-C: 1.07±0.26). This may indicate an intrinsic sensorimotor feedback mechanism for the DPN patients to regulate their gait. However, this feedback gets weaker as patients develop multiple complications. Further analysis with longer walking time and different speeds is needed to verify the entropy results.

Optimisation of rocker sole footwear for prevention of first plantar ulcer: comparison of group-optimised and individually-selected footwear designs

Background

Appropriate footwear for individuals with diabetes but no ulceration history could reduce the risk of first ulceration. However, individuals who deem themselves at low risk are unlikely to seek out bespoke footwear which is personalised. Therefore, our primary aim was to investigate whether group-optimised footwear designs, which could be prefabricated and delivered in a retail setting, could achieve appropriate pressure reduction, or whether footwear selection must be on a patient-by-patient basis. A second aim was to compare responses to footwear design between healthy participants and people with diabetes in order to understand the transferability of previous footwear research, performed in healthy populations.

Methods

Plantar pressures were recorded from 102 individuals with diabetes, considered at low risk of ulceration. This cohort included 17 individuals with peripheral neuropathy. We also collected data from 66 healthy controls. Each participant walked in 8 rocker shoe designs (4 apex positions × 2 rocker angles). ANOVA analysis was then used to understand the effect of two design features and descriptive statistics used to identify the group-optimised design. Using 200 kPa as a target, this group-optimised design was then compared to the design identified as the best for each participant (using plantar pressure data).

Results

Peak plantar pressure increased significantly as apex position was moved distally and rocker angle reduced (p < 0.001). The group-optimised design incorporated an apex at 52% of shoe length, a 20° rocker angle and an apex angle of 95°. With this design 71–81% of peak pressures were below the 200 kPa threshold, both in the full cohort of individuals with diabetes and also in the neuropathic subgroup. Importantly, only small increases (<5%) in this proportion were observed when participants wore footwear which was individually selected. In terms of optimised footwear designs, healthy participants demonstrated the same response as participants with diabetes, despite having lower plantar pressures.

Conclusions

This is the first study demonstrating that a group-optimised, generic rocker shoe might perform almost as well as footwear selected on a patient by patient basis in a low risk patient group. This work provides a starting point for clinical evaluation of generic versus personalised pressure reducing footwear.

Using Plantar Electrical Stimulation to Improve Postural Balance and Plantar Sensation Among Patients With Diabetic Peripheral Neuropathy: A Randomized Double Blinded Study

OBJECTIVE

People with diabetic peripheral neuropathy (DPN) often exhibit deteriorations in motor-performance mainly due to lack of plantar-sensation. The study explored effectiveness of plantar electrical-stimulation therapy to enhance motor-performance among people with DPN.

DESIGN AND METHODS

Using a double-blinded model, 28 volunteers with DPN (age: 57.8 ± 10.2 years) were recruited and randomized to either intervention (IG: n = 17) or control (CG: n = 11) group. Both groups received identical plantar-stimulation devices for six weeks of daily use at home; however, only the IG devices were set to deliver stimulation. Balance (ankle, hip, and center of mass [COM] sway) and gait (stride velocity [SV], stride time [ST], stride length [SL], and cadence) were measured using validated wearable sensors. Outcomes were assessed at baseline and at six-week. Clinical assessment including vascular as measured by ankle-brachial-index (ABI) and plantar-sensation as quantified by vibratory plantar threshold (VPT) were also measured at baseline and six weeks.

RESULTS

No difference were observed between groups for baseline characteristics ( P > .050). Posttherapy, ankle and COM sway with eyes open were significantly improved ( P < .05, Cohen's effect size d = 0.67-0.76) in the IG with no noticeable changes in CG. All gait parameters were significantly improved in the IG with highest effect size observed for cadence ( d = 1.35, P = .000). Results revealed improvement in VPT ( P = .004, d = 1.15) with significant correlation with stride velocity improvement ( r = .56, P = .037). ABI was improved in the IG in particulate among those with ABI>1.20 ( P = .041, d = 0.99) Conclusion: This study suggests that daily home use of plantar electrical-stimulation may be a practical means to enhance motor-performance and plantar-sensation in people with DPN.

An Optical-Fiber-Based Smart Textile (Smart Socks) to Manage Biomechanical Risk Factors Associated With Diabetic Foot Amputation

OBJECTIVE

This study aimed to validate a smart-textile based on fiber-optics for simultaneous measurement of plantar temperature, pressure, and joint angles in patients with diabetic peripheral neuropathy (DPN).

METHODS

After in-vitro validation in the laboratory, 33 eligible subjects with DPN were recruited (age: 58 ± 8 years, BMI: 31.5 ± 8 kg/m²) for assessing plantar pressure and temperature during habitual gait-speed in a clinical-setting. All participants were asked to walk at their habitual speed while wearing a pair of sensorized socks made from highly flexible fiber optics (SmartSox). An algorithm was designed to estimate temperature, pressure, and toe range of motion from optical wavelength generated from SmartSox. To validate the device, results from thermal stress response (TSR) using thermography and peak pressure measured by computerized pressure insoles (F-Scan) were used as gold standards.

RESULTS

In laboratory and under controlled conditions, the agreements for parameters of interest were excellent ( r > .98, P = .000), and no noticeable cross-talks between measurements of temperature, angle, and pressure were observed. During clinical data acquisition, a significant correlation was found for pressure profile under different anatomical regions of interest between SmartSox and F-Scan ( r = .67, P < .050) as well as between thermography and SmartSox ( r = .55, P < .050).

CONCLUSION

This study demonstrates the validity of an innovative smart textile for assessing simultaneously the key parameters associated with risk of foot ulcers in patients with DPN. It may empower clinicians to objectively stratify foot risk and provide timely care. Another study is warranted to validate its clinical application in preventing limb threating problems in patients with DPN.

Lace Up for Healthy Feet: The Impact of Shoe Closure on Plantar Stress Response

OBJECTIVE

This study examined the impact of shoe closure on plantar thermal stress response (TSR), which is known to be a surrogate of shear stress and skin perfusion. It is aimed to explore potential impact of shoe closure on increasing risk factors associated with plantar ulcers in people with diabetic peripheral neuropathy (DPN).

METHODS

Fifteen eligible subjects were enrolled. The left foot was used as a reference and fitted to a self-adjusted and habitual lace-tightening method by each subject. The right foot was used as a test closure and fitted into three lace closure conditions: loose, tight, and preset optimal closure (reel clutch, BOA technology). Thermal images were taken after 5 minutes of acclimatization (pre-trial) and immediately after 200 walking steps in each shoe closure condition (post-trial). TSR was calculated from the thermal images.

RESULTS

TSR was significantly higher in the test closure with loose (70.24%, P = .000) and tight (66.85%, P = .007) and lower (-206.53%, P = .000) in the preset optimal closure when compared to the reference closure. Only lace closure conditions affected TSR with no significant impact from age, BMI, and gender in our sample in a multivariable regression model.

CONCLUSION

The results from this study suggest that shoelace closure technique can have a profound effect on TSR. It therefore stands to reason that optimal lace closure may have an impact in reducing risk of plantar ulcers in people with DPN. Interestingly, results revealed that even a self-adjusted lace closure may not be necessarily optimal and a preset closure setting like reel clutch might ultimately be recommended to minimize risk. Further study is warranted to confirm or refute these interesting results.