A study of biomechanical parameters in gait analysis and sensitive cronaxie of diabetic neuropathic patients

Sensorimotor Training Improves Gait, Ankle Joint Proprioception, and Quality of Life in Patients With Diabetic Peripheral Neuropathy: A Single-Blinded Randomized Controlled Trial

OBJECTIVE

To investigate the effect of sensorimotor training on gait, ankle joint proprioception, and quality of life in diabetic peripheral neuropathy patients.

DESIGN

A prospective, single-blind, randomized controlled experiment was performed. Forty patients with diabetic peripheral neuropathy aged 50-65 yrs were distributed randomly into two groups, the sensorimotor training group ( n = 20), and the control group ( n = 20). Both groups attended awareness sessions about diabetes and foot care for 30 mins, every 2 wks. Moreover, the sensorimotor training group received 6 wks (3 d/wk) of sensorimotor training. Spatiotemporal gait parameters, proprioception accuracy of the ankle joint, and quality of life were measured before and after 6 wks of intervention.

RESULTS

Regarding baseline data, no significant differences were identified among groups ( P > 0.05). After 6-wk intervention, the sensorimotor training group exhibited significant improvements in all outcome variables ( P < 0.001), while the control group showed significant changes in quality of life only ( P = 0.03). Comparing groups after intervention reveals statistically significant differences in all measured variables in favor of the sensorimotor training group ( P < 0.001).

CONCLUSIONS

Sensorimotor training may improve spatiotemporal gait parameters, ankle joint proprioception, and quality of life of patients with diabetic peripheral neuropathy.

Impact of diabetic peripheral neuropathy on gait abnormalities in patients with type 2 diabetes mellitus

Background

Many patients with type 2 diabetes (T2DM) suffer from diabetic peripheral neuropathy (DPN) and impaired muscle coordination. These changes may lead to walking instability, and gait abnormalities resulting in increased fall risk and lower limb amputations. The aim of this study was to assess the impact of DPN and patient footwear on the gait in patients with diabetes, in addition to Comparing the peak plantar pressure (PPP) in patients with and without DPN and assessing its association with gait abnormalities.

Methodology

This is an observational case-control study. Forty Subjects with T2DM were divided into two age and sex-matched groups, 20 subjects each. Group A: subjects with DPN. Group B: subjects without DPN. All study participants were subjected to a thorough history taking, clinical examinations focusing on detailed foot examination, PPP assessment, and functional gait evaluation.

Results

The results obtained in this study showed a median gait assessment score of 21 (17.0-22.5) for group A and 26 (23.5-26.0) for group B which was statistically significant (p < 0.001). There was no statistically significant difference between both groups (p > 0.05) regarding the assessment of footwear appropriateness. Comparing the PPP measurement among both studied groups, the prevalence of an elevated PPP was 80% in group A compared to 65% in group B, which was statistically non-significant, p = 0.288.

Conclusions

Gait abnormalities are common among patients with T2DM even in the absence of DPN. However, the presence of DPN was the strongest independent risk factor for gait abnormalities among the studied factors.

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.

Impact of biomechanics on therapeutic interventions and rehabilitation for major chronic musculoskeletal conditions: A 50-year perspective

The pivotal role of biomechanics in the past 50 years in consolidating the basic knowledge that underpins prevention and rehabilitation measures has made this area a great spotlight for health practitioners. In clinical practice, biomechanics analysis of spatiotemporal, kinematic, kinetic, and electromyographic data in various chronic conditions serves to directly enhance deeper understanding of locomotion and the consequences of musculoskeletal dysfunctions in terms of motion and motor control. It also serves to propose straightforward and tailored interventions. The importance of this approach is supported by myriad biomechanical outcomes in clinical trials and by the development of new interventions clearly grounded on biomechanical principles. Over the past five decades, therapeutic interventions have been transformed from fundamentally passive in essence, such as orthoses and footwear, to emphasizing active prevention, including exercise approaches, such as bottom-up and top-down strengthening programs for runners and people with osteoarthritis. These approaches may be far more effective inreducing pain, dysfunction, and, ideally, incidence if they are based on the biomechanical status of the affected person. In this review, we demonstrate evidence of the impact of biomechanics and motion analysis as a foundation for physical therapy/rehabilitation and preventive strategies for three chronic conditions of high worldwide prevalence: diabetes and peripheral neuropathy, knee osteoarthritis, and running-related injuries. We conclude with a summary of recommendations for future studies needed to address current research gaps.

Cognitive function and cardiorespiratory fitness affect gait speed in type-2 diabetic patients without neuropathy

AIM

To identify physical, cognitive, and metabolic factors affecting gait speed in patients with type-2 diabetes mellitus (T2DM) without neuropathy.

METHODS

This cross-sectional study enrolled 71 diabetic patients without neuropathy (mean age 55.87±7.74 years, 85.9% women). Neuropathy status was assessed with Douleur Neuropathique 4. We used a cut-off point for gait speed of 1 m/s to classify the participants into two groups: slow walkers (SW) and average and brisk walkers (ABW). The groups were compared in terms of age, sex, body mass index (BMI), hemoglobin A1c (HbA1c), fasting glucose, systolic blood pressure, maximal aerobic capacity (VO2 max), percentage of muscle mass, percentage of lower extremity muscle mass, Mini-Mental State Examination (MMSE) score, and years of education.

RESULTS

Compared with the ABW group, the SW group had significantly lower VO2 max (14.49±2.95 vs 16.25±2.94 mL/kg/min) and MMSE score (25.01±3.21 vs 27.35±1.97), fewer years of education, and these patients were more frequently women (P<0.05). In the multivariate regression models, the combination of VO2 max, sex, and MMSE score explained only 23.5% of gait speed (P<0.001). MMSE score and VO2max independently determined gait speed after adjustment for age, BMI, HbA1c, fasting glucose, systolic blood pressure, percent of muscle mass, percent of lower extremity muscle mass, and years of education.

CONCLUSION

In diabetic patients without neuropathy, physical impairment and disability could be prevented by an improvement in aerobic capacity and cognitive function.

Machine Learning-Based Diabetic Neuropathy and Previous Foot Ulceration Patients Detection Using Electromyography and Ground Reaction Forces during Gait

Diabetic neuropathy (DN) is one of the prevalent forms of neuropathy that involves alterations in biomechanical changes in the human gait. Diabetic foot ulceration (DFU) is one of the pervasive types of complications that arise due to DN. In the literature, for the last 50 years, researchers have been trying to observe the biomechanical changes due to DN and DFU by studying muscle electromyography (EMG) and ground reaction forces (GRF). However, the literature is contradictory. In such a scenario, we propose using Machine learning techniques to identify DN and DFU patients by using EMG and GRF data. We collected a dataset from the literature which involves three patient groups: Control (n = 6), DN (n = 6), and previous history of DFU (n = 9) and collected three lower limb muscles EMG (tibialis anterior (TA), vastus lateralis (VL), gastrocnemius lateralis (GL)), and three GRF components (GRFx, GRFy, and GRFz). Raw EMG and GRF signals were preprocessed, and different feature extraction techniques were applied to extract the best features from the signals. The extracted feature list was ranked using four different feature ranking techniques, and highly correlated features were removed. In this study, we considered different combinations of muscles and GRF components to find the best performing feature list for the identification of DN and DFU. We trained eight different conventional ML models: Discriminant analysis classifier (DAC), Ensemble classification model (ECM), Kernel classification model (KCM), k-nearest neighbor model (KNN), Linear classification model (LCM), Naive Bayes classifier (NBC), Support vector machine classifier (SVM), and Binary decision classification tree (BDC), to find the best-performing algorithm and optimized that model. We trained the optimized the ML algorithm for different combinations of muscles and GRF component features, and the performance matrix was evaluated. Our study found the KNN algorithm performed well in identifying DN and DFU, and we optimized it before training. We found the best accuracy of 96.18% for EMG analysis using the top 22 features from the chi-square feature ranking technique for features from GL and VL muscles combined. In the GRF analysis, the model showed 98.68% accuracy using the top 7 features from the Feature selection using neighborhood component analysis for the feature combinations from the GRFx-GRFz signal. In conclusion, our study has shown a potential solution for ML application in DN and DFU patient identification using EMG and GRF parameters. With careful signal preprocessing with strategic feature extraction from the biomechanical parameters, optimization of the ML model can provide a potential solution in the diagnosis and stratification of DN and DFU patients from the EMG and GRF signals.

Abnormal vibration perception threshold alters the gait features in type 2 diabetes mellitus patients

OBJECTIVE

It is generally believed that gait characteristics of diabetic neuropathic patients differ from those of non-diabetic ones. However, it is still unclear how the abnormal foot sensation influences the gait during walking in type 2 diabetes mellitus (T2DM). For the purpose of gaining a better insight into the alterations of detailed gait parameters and figuring out important aspects in the gait indexes by peripheral neuropathy in elder T2DM patients, we compared the gait features in participants with normal glucose tolerance (NGT) controls and diabetic individuals complicated by peripheral neuropathy or not.

SUBJECTS AND METHODS

Gait parameters were observed during the 10-m walk on flat land among different conditions of diabetes in 1,741 participants from three clinical centers. Subjects were divided into four groups: persons with NGT were taken as the control group; patients with T2DM included three subgroups: DM control (no chronic complications), DM-DPN (DM complicated by only peripheral neuropathy), and DM-DPN+LEAD (DM complicated by both neuropathy and artery disease). The clinical characteristics and gait parameters were assessed and compared among these four groups. Analyses of variance were employed to verify possible differences of gait parameters between groups and conditions. Stepwise multivariate regression analysis was performed to reveal possible predictors of gait deficits. Receiver operating characteristic (ROC) curve analysis was employed to find any discriminatory power of diabetic peripheral neuropathy (DPN) for the step time.

RESULTS

In participants burdened with DPN, whether complicated by lower extremity arterial disease (LEAD) or not, step time increased sharply (p < 0.05). Stepwise multivariate regression models showed that independent variables of gait abnormality were sex, age, leg length, vibration perception threshold (VPT), and ankle-brachial index (ABI) (p < 0.01). Meanwhile, VPT was a significant independent predictor of step time, spatiotemporal variability (SD_A), and temporal variability (SD_B) (p < 0.05). ROC curve analysis was explored to find the discriminatory power of DPN for the occurrence of increased step time. The area under the curve (AUC) value was 0.608 (95% CI: 0.562-0.654, p < 0.01), and the cutoff point was 538.41 ms accompanied by a higher VPT. A significant positive association was observed between increased step time and the highest VPT group [odds ratio (OR) = 1.83, 95% CI: 1.32-2.55, p< 0.01]. In female patients, this OR value elevated to 2.16 (95% CI: 1.25-3.73, p< 0.01).

CONCLUSIONS

In addition to sex, age, and leg length, VPT was a distinct factor that associated with altered gait parameters. DPN is associated with increased step time, and the step time increases with worsening VPT in type 2 diabetes.

Two-Week Rehabilitation with Auditory Biofeedback Prosthesis Reduces Whole Body Angular Momentum Range during Walking in Stroke Patients with Hemiplegia: A Randomized Controlled Trial

Walking rehabilitation is challenging in stroke patients with sensory impairments. In this study, we examined the two-week effect of an auditory biofeedback prosthesis, Auditory Foot (AF), on the change in the frontal whole body angular momentum (WBAM) range, before and after a two-week walking rehabilitation. We conducted a pilot randomized controlled trial (RCT). We employed statistical Bayesian modeling to understand the mechanism of the rehabilitation effect and predict the expected effect in new patients. The best-performing model indicated that the frontal WBAM range was reduced in the AF group by 12.9–28.7%. This suggests that the use of kinesthetic biofeedback in gait rehabilitation contributes to the suppression of frontal WBAM, resulting in an improved walking balance function in stroke patients.

Wearable Sensor for Assessing Gait and Postural Alterations in Patients with Diabetes: A Scoping Review

Background and Objectives: Diabetes mellitus is considered a serious public health problem due to its high prevalence and related complications, including gait and posture impairments due to neuropathy and vascular alterations and the subsequent increased risk of falls. The gait of patients with diabetes is characterized by alterations of the main spatiotemporal gait parameters such as gait velocity, cadence, stride time and length, which are also known to worsen with disease course. Wearable sensor systems can be used for gait analysis by providing spatiotemporal parameters and postural control (evaluated from the perspective of body sway), useful for investigating the disease progression. Thanks to their small size and low cost of their components, inertial measurement units (IMUs) are easy to wear and are cheap tools for movement analysis. Materials and Methods: The aim of this study is to review articles published in the last 21 years (from 2000 to 2021) concerning the application of wearable sensors to assess spatiotemporal parameters of gait and body postural alterations in patients with diabetes mellitus. Relevant articles were searched in the Medline database using PubMed, Ovid and Cochrane libraries. Results: One hundred and four articles were initially identified while searching the scientific literature on this topic. Thirteen were selected and analysed in this review. Wearable motion sensors are useful, noninvasive, low-cost, and objective tools for performing gait and posture analysis in diabetic patients. The IMUs can be worn at the lumber levels, tibias or feet, and different spatiotemporal parameters of movement and static posture can be assessed. Conclusions: Future research should focus on standardizing the measurement setup and selecting the most informative spatiotemporal parameters for gait and posture analysis.

Performance analysis of noninvasive electrophysiological methods for the assessment of diabetic sensorimotor polyneuropathy in clinical research: a systematic review and meta-analysis with trial sequential analysis

Despite the availability of various clinical trials that used different diagnostic methods to identify diabetic sensorimotor polyneuropathy (DSPN), no reliable studies that prove the associations among diagnostic parameters from two different methods are available. Statistically significant diagnostic parameters from various methods can help determine if two different methods can be incorporated together for diagnosing DSPN. In this study, a systematic review, meta-analysis, and trial sequential analysis (TSA) were performed to determine the associations among the different parameters from the most commonly used electrophysiological screening methods in clinical research for DSPN, namely, nerve conduction study (NCS), corneal confocal microscopy (CCM), and electromyography (EMG), for different experimental groups. Electronic databases (e.g., Web of Science, PubMed, and Google Scholar) were searched systematically for articles reporting different screening tools for diabetic peripheral neuropathy. A total of 22 studies involving 2394 participants (801 patients with DSPN, 702 controls, and 891 non-DSPN patients) were reviewed systematically. Meta-analysis was performed to determine statistical significance of difference among four NCS parameters, i.e., peroneal motor nerve conduction velocity, peroneal motor nerve amplitude, sural sensory nerve conduction velocity, and sural sensory nerve amplitude (all p < 0.001); among three CCM parameters, including nerve fiber density, nerve branch density, and nerve fiber length (all p < 0.001); and among four EMG parameters, namely, time to peak occurrence (from 0 to 100% of the stance phase) of four lower limb muscles, including the vastus lateralis (p < 0.001), tibialis anterior (p = 0.63), lateral gastrocnemius (p = 0.01), and gastrocnemius medialis (p = 0.004), and the vibration perception threshold (p < 0.001). Moreover, TSA was conducted to estimate the robustness of the meta-analysis. Most of the parameters showed statistical significance between each other, whereas some were statistically nonsignificant. This meta-analysis and TSA concluded that studies including NCS and CCM parameters were conclusive and robust. However, the included studies on EMG were inconclusive, and additional clinical trials are required.

A Systematic Approach to the Design and Characterization of A Smart Insole for Detecting Vertical Ground Reaction Force (vGRF) in Gait Analysis

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.

Gait Biomarkers Classification by Combining Assembled Algorithms and Deep Learning: Results of a Local Study

Machine learning, one of the core disciplines of artificial intelligence, is an approach whose main emphasis is analytical model building. In other words, machine learning enables an automaton to make its own decisions based on a previous training process. Machine learning has revolutionized every research sector, including health care, by providing precise and accurate decisions involving minimal human interventions through pattern recognition. This is emphasized in this research, which addresses the issue of “support for diabetic neuropathy (DN) recognition.” DN is a disease that affects a large proportion of the global population. In this research, we have used gait biomarkers of subjects representing a particular sector of population located in southern Mexico to identify persons suffering from DN. To do this, we used a home-made body sensor network to capture raw data of the walking pattern of individuals with and without DN. The information was then processed using three sampling criteria and 23 assembled classifiers, in combination with a deep learning algorithm. The architecture of the best combination was chosen and reconfigured for better performance. The results revealed a highly acceptable classification with greater than 85% accuracy when using these combined approaches.

NurseNet: Monitoring Elderly Levels of Activity with a Piezoelectric Floor

Monitoring the activity of elderly individuals in nursing homes is key, as it has been shown that physical activity leads to significant health improvement. In this work, we introduce NurseNet, a system that combines an unobtrusive, affordable, and robust piezoelectric floor sensor with a convolutional neural network algorithm, which aims at measuring elderly physical activity. Our algorithm is trained using signal embedding based on atoms of a pre-learned dictionary and focuses the network's attention on step-related signals. We show that NurseNet is able to avoid the main limitation of floor sensors by recognizing relevant signals (i.e., signals produced by patients) and ignoring events related to the medical staff, offering a new tool to monitor elderly activity in nursing homes efficiently.

Plantar pressure distribution in diverse stages of diabetic neuropathy

Background

Diabetic Foot Ulceration in patients with diabetes could be associated with high plantar pressure caused by diabetes neuropathy. Therefore, it seems that one of the ways of identifying high-risk legs in diabetic patients with neuropathy would be characterization of elevated plantar pressure distributions.

Objective

Comparing the plantar pressure distribution in diabetic patients who suffered neuropathy with those without neuropathy.

Methods and materials

Plantar pressure distribution was recorded in the following categories: 38 diabetic patients without neuropathy, 30, 40 and 34 patients with mild neuropathy, moderate and severe neuropathy respectively.

Results

Patients suffered from severe neuropathy suggested higher maximum peak plantar pressure at midfoot, heel, and medial forefoot. The peak pressure of midfoot was significantly different in the following categories as well: patient without neuropathy (32.3 ± 17.9 kPa), mild neuropathic (24.0 ± 17.9 kPa), moderate neuropathic (21.5 ± 12.6 kPa), and severe neuropathic (22.9 ± 10.7 kPa) groups (p = 0.02).

Conclusion

The progression of diabetic neuropathy would have been increased followed by the peak plantar pressure.

Vertical displacement of the centre of mass during walking in people with diabetes and diabetic neuropathy does not explain their higher metabolic cost of walking

People with diabetes display biomechanical gait alterations compared to controls and have a higher metabolic cost of walking (CoW), but it remains unknown whether differences in the vertical displacement of the body centre of mass (CoM) may play a role in this higher CoW. The aim of this study was to investigate vertical CoM displacement (and step length as a potential underpinning factor) as an explanatory factor in the previously observed increased CoW with diabetes. Thirty-one non-diabetic controls (Ctrl); 22 diabetic patients without peripheral neuropathy (DM) and 14 patients with moderate/severe Diabetic Peripheral Neuropathy (DPN), underwent gait analysis using a motion analysis system and force plates while walking at a range of matched speeds between 0.6 and 1.6 m/s. Vertical displacement of the CoM was measured over the gait cycle, and was not different in either diabetes patients with or without diabetic peripheral neuropathy compared to controls across the range of matched walking speeds examined (at 1 m/s: Ctrl: 5.59 (SD: 1.6), DM: 5.41 (1.63), DPN: 4.91 (1.66) cm; p > 0.05). The DPN group displayed significantly shorter steps (at 1 m/s: Ctrl: 69, DM: 67, DPN: 64 cm; p > 0.05) and higher cadence (at 1 m/s: Ctrl: 117 (SD1.12), DM: 119 (1.08), DPN: 122 (1.25) steps per minute; p > 0.05) across all walking speeds compared to controls. The vertical CoM displacement is therefore unlikely to be a factor in itself that contributes towards the higher CoW observed recently in people with diabetic neuropathy. The higher CoW in patients with diabetes may not be explained by the CoM displacement, but rather may be more related to shorter step lengths, increased cadence and the associated increased internal work and higher muscle forces developed by walking with more flexed joints.

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.

Reactive balance control in older adults with diabetes

Diabetes mellitus is a major health problem for older adults worldwide and could be associated with impaired ability to recover balance after postural disturbances. This study compared reactive balance control in three groups of adults, young (YA), healthy non-diabetes older (nonDM-OA) and diabetes older (DM-OA). Twenty participants in each group completed a series of vision, plantar cutaneous sensitivity, grip power and lower limb strength tests. In the reactive balance test, participants stood on a force platform and used the dominant hand to pull the handle of a cord that could be suddenly released to create an imbalancing force. The anteroposterior (AP) and mediolateral (ML) motion of the center of pressure (COP) immediately after the sudden release was calculated to represent the level of imbalance experienced by the participants. Regression analysis entering big toe plantar sensitivity and grip power as independent variable was conducted for COP range for the three groups separately. The results showed that, except for the knee extensor, DM-OA had significantly poorer muscle strength and plantar sensitivity, and greater COP ML motion than YA and nonDM-OA. DM-OA also had significantly greater COP AP motion than YA. Grip power alone and together with plantar sensitivity explained a significant amount of variance in the AP and ML COP motion respectively (r² = 0.334 and 0.582, respectively) for DM-OA. These findings indicated that diabetes in older adults was associated with declines in reactive balance control, and these changes may be related to muscle weakness and plantar insensitivity.

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.

The Effect of Diabetic Peripheral Neuropathy on Ground Reaction Forces during Straight Walking in Stroke Survivors

Purpose. The aim of this present study was to investigate the ground reaction forces (GRFs) alterations in stroke survivors with diabetic peripheral neuropathy (DPN). Methods. Ten stroke survivors with DPN, 10 stroke survivors without DPN, and 10 healthy controls with matched body weight between groups participated in this case-control cross-sectional study. Three-dimensional GRFs (anterior-posterior, medial-lateral, and vertical) were collected at a comfortable walking speed using the Nexus Vicon motion analysis system and force plate. The Kruskal–Wallis test was used to analyze GRFs parameters. Results. We found significant alterations of medial-lateral forces of the nonparetic side and vertical forces of the paretic side in stroke survivors with DPN compared to stroke survivors without DPN and healthy controls. In addition, there were smaller braking and lower propulsion peak in anterior-posterior forces, smaller magnitude of medial-lateral forces, and lower first and second peak of vertical forces in stroke survivors with DPN compared to stroke survivors without DPN and healthy controls. Conclusion. The study findings identified that GRFs were affected in stroke survivors with DPN on both the paretic and the nonparetic sides. Further investigations are warranted to explore the impact of DPN on the kinematics and muscle activity related to the gait performance in stroke survivors with DPN.

Gait parameters of people with diabetes-related neuropathic plantar foot ulcers

BACKGROUND

Foot ulceration associated with diabetic peripheral neuropathy is a global concern. Biomechanical investigation allows the identification of gait abnormalities that may adversely affect ulcer healing. The objective of this case-control study was to compare the gait parameters of cases with diabetes-related foot ulcers to controls.

METHODS

Three-dimensional movement analyses were performed on 21 people with diabetes-related neuropathic plantar foot ulcers (cases), 69 people with diabetes without a foot ulcer history (diabetes controls) and 56 healthy controls. Outcome data were reported as mean differences, 95% confidence intervals and Cohen's d effect sizes. Binary logistic regressions were used to adjust for age, sex and body mass index.

FINDINGS

People with foot ulcers had a smaller plantar flexion (Cohen's d=-0.6 vs. diabetes controls and d=-0.8 vs. healthy controls), knee flexion (d=-0.6 vs. diabetes controls and d=-1.0 vs. healthy controls) and pelvic obliquity (d=-0.9 vs. diabetes controls and d=-0.7 vs. healthy controls) (all P<0.05). They also had a significantly greater range of anterior-posterior ground reaction force (d=1.0 vs. diabetes controls and d=1.7 vs. healthy controls) and total vertical ground reaction force (d=0.9 vs. diabetes controls and d=1.1 vs. healthy controls) and significantly slower walking speed and smaller step length compared to controls (all P<0.05).

INTERPRETATION

People with plantar foot ulcers have considerably different gait parameters to controls. Whether the observed gait parameters contributed to the ulcer development or are a response to the ulcer is currently unclear and needs further investigation.

Short-Term Effect of Prosthesis Transforming Sensory Modalities on Walking in Stroke Patients with Hemiparesis

Sensory impairments caused by neurological or physical disorders hamper kinesthesia, making rehabilitation difficult. In order to overcome this problem, we proposed and developed a novel biofeedback prosthesis called Auditory Foot for transforming sensory modalities, in which the sensor prosthesis transforms plantar sensations to auditory feedback signals. This study investigated the short-term effect of the auditory feedback prosthesis on walking in stroke patients with hemiparesis. To evaluate the effect, we compared four conditions of auditory feedback from plantar sensors at the heel and fifth metatarsal. We found significant differences in the maximum hip extension angle and ankle plantar flexor moment on the affected side during the stance phase, between conditions with and without auditory feedback signals. These results indicate that our sensory prosthesis could enhance walking performance in stroke patients with hemiparesis, resulting in effective short-term rehabilitation.

The effects of Task-Oriented Motor Training on gait characteristics of patients with type 2 diabetes neuropathy

Background

It is known that general gait training improves lower extremity muscle strength and endurance in Diabetes Neuropathy (DN). But, it is still unknown whether Task-Oriented (TO) gait training would change gait biomechanics and the risk of falling in DN. TO gait training focuses on promoting timing and coordination of lower extremity movements through goal-directed practices with sufficient repetition.

Methods

A group of 14 patients with DN participated in a time-series study. All subjects participated in four sessions of assessments (Initial, Pre, Post and Follow-Up). Training was twice a week for 12 weeks. Vertical and horizontal Ground Reaction Forces (GRF), Time Get up and Go (TGUG) and Fall Efficacy Scale-International (FES-I) were evaluated. Gait training started with stepping patterns that progressively changed to complicated patterns of walking. Then, training continued combining walking patterns with upper extremity activities and then ended with treadmill-paced practice.

Results

DN patients significantly increased Second Vertical Peak Force and Horizontal Propulsive Force in addition decrease in Minimum Vertical Force. TGUG significantly decreased while FES-I reflected significant increase after gait training.

Discussion

Conclusively, training not only improved gait performance, confidence in daily activities and attenuated risk of falling, but also helped DN patients to improve feet biomechanics, muscles timing and coordination.

Conclusions

Gait training with respect to principles of motor learning allowed patients to effectively improve through sessions.

Alterations in the lower limb joint moments precede the peripheral neuropathy diagnosis in diabetes patients

BACKGROUND

Changes in gait patterns in individuals with diabetes and neuropathy are still inconclusive. Our aim was to identify differences in the net intralimb moments distribution and lower limb kinematics during gait in different stage of diabetes.

SUBJECTS AND METHODS

This was an observational cross-sectional study that assessed 38 adults: a control group (n=12), a group with diabetes (n=12), and a group with diabetic neuropathy (n=14). The flexor and extensor joint moment peaks and kinematics of ankle, knee, and hip angles were compared among groups (by analysis of variance).

RESULTS

At initial contact, both diabetes groups present more hip flexion and smaller hip extensor moment. During late midstance, hip extension decreases, and flexion moment increases in both diabetes groups. For the same diabetes groups, during push off, the hip is more flexed, and the hip extensor moment decreases. Only for the diabetes group without neuropathy is the knee markedly more flexed, and the extensor moment is higher than in the other groups. At push off, the ankle is less extended in both diabetes groups, but the ankle extensor moment is significantly smaller only in neuropathic subjects.

CONCLUSIONS

The biomechanical modifications on the gait appeared to be a continuous process that was already revealed in patients without neuropathy. The use of the hip joint as a mechanism of forward progression of the body, instead of using the ankle, was more evident and consistent for the patients with diabetic neuropathy. The knee seems to have a major role in those with diabetes without neuropathy who presented higher extensor moments to support the body during early stance.

Gait characteristics of people with diabetes-related peripheral neuropathy, with and without a history of ulceration

Biomechanical alterations in diabetes are believed to contribute to plantar neuropathic ulceration. This exploratory study documents clinical measures of flexibility and strength, alongside three-dimensional biomechanical gait data of the lower limb, in 10 patients with a history of neuropathic ulceration (DNU; n=10). Comparative data is presented from age and gender matched groups with; diabetes peripheral neuropathy and no ulcer history (DWN; n=10), diabetes and no peripheral neuropathy (DNN; n=10) and a non-diabetes reference group (NOND; n=10). Biomechanical data were collected at a comfortable walking speed with a Vicon motion analysis system. Clinical measures showed a non-significant trend toward decreased static range of motion at the ankle and first metatarsophalangeal joints, with worsening neuropathy status. Of the diabetes groups, knee and ankle strength was significantly lower in those with an ulcer history (p=0.01-0.03), with the exception of knee extension. In the DNU group, walking speed was on average 0.17 ms slower compared to NOND (p=0.04). The DNU group demonstrated a lower range of motion than NOND at the: hips (frontal plane, by 25%: p=0.03); hips and knees (transverse plane, 31%: p=0.01 and 32%: p<0.01); ankles (sagittal plane, 22%: p<0.01) and first metatarsophalangeal joints (sagittal plane, 32%: p=0.01), with less foot rotation (24%: p=0.04). Kinetic alterations in DNU included lower: ankle maximum power (21%: p=0.03) and vertical ground reaction force 2nd peak (6%: p<0.01). The study findings identified gait alterations in people with clinically severe peripheral neuropathy and related plantar foot ulcer history. Further research is needed to explore potential casual pathways.

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n=94), without polyneuropathy (n=39) and healthy elderly (n=19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r=-.749, p<.001 at the imposed, and r=-.693, p<.001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r=-.837, p<.001 at the imposed, and r=-.731, p<.001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.

Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia

OBJECTIVE

To use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in persons with spinal cord injury (SCI) during powered exoskeleton-assisted walking.

RESEARCH DESIGN

A cross-sectional study was performed to analyze vGRF during powered exoskeleton-assisted walking (ReWalk™: Argo Medical Technologies, Inc, Marlborough, MA, USA) compared with vGRF of able-bodied gait.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

Six persons with thoracic motor-complete SCI (T1-T11 AIS A/B) and three age-, height-, weight- and gender-matched able-bodied volunteers participated.

INTERVENTIONS

SCI participants were trained to ambulate over ground using a ReWalk™. vGRF was recorded using the F-Scan™ system (TekScan, Boston, MA, USA).

OUTCOME MEASURES

Peak stance average (PSA) was computed from vGRF and normalized across all participants by percent body weight. Peak vGRF was determined for heel strike, mid-stance, and toe-off. Relative linear impulse and harmonic analysis provided quantitative support for analysis of powered exoskeletal gait.

RESULTS

Participants with motor-complete SCI, ambulating independently with a ReWalk™, demonstrated mechanical loading magnitudes and patterns similar to able-bodied gait. Harmonic analysis of PSA profile by Fourier transform contrasted frequency of stance phase gait components between able-bodied and powered exoskeleton-assisted walking.

CONCLUSION

Powered exoskeleton-assisted walking in persons with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. This suggests the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities. vGRF profile can be used to examine both magnitude of loading and gait mechanics of powered exoskeleton-assisted walking among participants of different weight, gait speed, and level of assist.

Effects of a combined strengthening, stretching and functional training program versus usual-care on gait biomechanics and foot function for diabetic neuropathy: a randomized controlled trial

Background

Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation.

Methods/Design

A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition.

Discussion

Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease.

Trial Registration

ClinicalTrials.gov Identifier: NCT01207284

Electromyography and kinematic changes of gait cycle at different cadences in diabetic neuropathic individuals

INTRODUCTION

Changes in gait cadence caused by challenging situations in daily life might induce higher demand for strength and propulsion in diabetic neuropathic (DN) subjects.

METHODS

Forty-six subjects (healthy and DN) walked at two cadences (self-selected and 25% higher). Kinematic and electromyographic data were obtained from lower limbs and compared across the gait cycle.

RESULTS

DN subjects showed a delayed peak in plantarflexor activity along the whole cycle (irrespective of cadence) compared with healthy subjects. However, during the imposed cadence, DN individuals showed reduced ankle range of motion along the entire cycle compared with the self-selected condition and healthy individuals walking at both cadences (P = 0.002).

CONCLUSIONS

These findings suggest that when diabetic individuals face a new challenging situation that induces a higher demand for muscle strength and propulsion, the necessary range of motion and neuromuscular control around distal joints are insufficient.

Experimental calf muscle pain attenuates the postural stability during quiet stance and perturbation

BACKGROUND

The purpose of this study was to evaluate how acute pain changes the postural control and stability during quiet standing and after unexpected perturbations.

METHODS

Nine subjects stood as quiet as possible on a movable force platform that recorded the centre of pressure position and provided unexpected floor perturbations, before, during and after experimental calf muscle pain. Bilateral surface electromyography from the tibialis anterior and medial gastrocnemius muscles was recorded. The foot pressure distributions were measured using pressure insoles. Intramuscular injections of hypertonic saline were administrated (right leg) to induce acute pain in the tibialis anterior and/or medial gastrocnemius muscles, and an isotonic injection was used as control.

FINDINGS

Simultaneous pain in tibialis anterior and medial gastrocnemius altered the postural control. During quiet standing: higher medial-lateral centre of pressure speed and increased total sway displacement (P<0.05), weight moved to the non-painful side, (P<0.05) and plantar centre of pressure of the left foot was shifted towards the heel's direction (P<0.05). During forward perturbation: higher mean displacement in the medial-lateral direction (P<0.05). After the perturbation: larger sway area (P<0.05). Pain only in the medial gastrocnemius muscle increased medial-lateral centre of pressure speed (P<0.05) during the quiet standing. Pain only in the tibialis anterior muscle increased peak pressure on the contralateral foot (P<0.05).

INTERPRETATION

These findings suggest that large acute painful areas on the calf muscles impair the postural control and potentially increase the risk factors for falls. Further strategies aiming to reduce pain in patients may lead to improvement in balance.

A comparison of lower limb EMG and ground reaction forces between barefoot and shod gait in participants with diabetic neuropathic and healthy controls

Background

It is known that when barefoot, gait biomechanics of diabetic neuropathic patients differ from non-diabetic individuals. However, it is still unknown whether these biomechanical changes are also present during shod gait which is clinically advised for these patients. This study investigated the effect of the participants own shoes on gait biomechanics in diabetic neuropathic individuals compared to barefoot gait patterns and healthy controls.

Methods

Ground reaction forces and lower limb EMG activities were analyzed in 21 non-diabetic adults (50.9 ± 7.3 yr, 24.3 ± 2.6 kg/m²) and 24 diabetic neuropathic participants (55.2 ± 7.9 yr, 27.0 ± 4.4 kg/m²). EMG patterns of vastus lateralis, lateral gastrocnemius and tibialis anterior, along with the vertical and antero-posterior ground reaction forces were studied during shod and barefoot gait.

Results

Regardless of the disease, walking with shoes promoted an increase in the first peak vertical force and the peak horizontal propulsive force. Diabetic individuals had a delay in the lateral gastrocnemius EMG activity with no delay in the vastus lateralis. They also demonstrated a higher peak horizontal braking force walking with shoes compared to barefoot. Diabetic participants also had a smaller second peak vertical force in shod gait and a delay in the vastus lateralis EMG activity in barefoot gait compared to controls.

Conclusions

The change in plantar sensory information that occurs when wearing shoes revealed a different motor strategy in diabetic individuals. Walking with shoes did not attenuate vertical forces in either group. Though changes in motor strategy were apparent, the biomechanical did not support the argument that the use of shoes contributes to altered motor responses during gait.

Plantar pressure distribution patterns during gait in diabetic neuropathy patients with a history of foot ulcers

OBJECTIVE

To investigate and compare the influence of a previous history of foot ulcers on plantar pressure variables during gait of patients with diabetic neuropathy.

INTRODUCTION

Foot ulcers may be an indicator of worsening diabetic neuropathy. However, the behavior of plantar pressure patterns over time and during the progression of neuropathy, especially in patients who have a clinical history of foot ulcers, is still unclear.

METHODS

Subjects were divided into the following groups: control group, 20 subjects; diabetic neuropathy patients without foot ulcers, 17 subjects; and diabetic neuropathy patients with at least one healed foot ulcer within the last year, 10 subjects. Plantar pressure distribution was recorded during barefoot gait using the Pedar-X system.

RESULTS

Neuropathic subjects from both the diabetic neuropathy and DNU groups showed higher plantar pressure than control subjects. At midfoot, the peak pressure was significantly different among all groups: control group (139.4+/-76.4 kPa), diabetic neuropathy (205.3+/-118.6 kPa) and DNU (290.7+/-151.5 kPa) (p=0.008). The pressure-time integral was significantly higher in the ulcerated neuropathic groups at midfoot (CG: 37.3+/-11.4 kPa.s; DN: 43.3+/-9.1 kPa.s; DNU: 68.7+/-36.5 kPa.s; p=0.002) and rearfoot (CG: 83.3+/-21.2 kPa.s; DN: 94.9+/-29.4 kPa.s; DNU: 102.5+/-37.9 kPa.s; p=0.048).

CONCLUSION

A history of foot ulcers in the clinical history of diabetic neuropathy subjects influenced plantar pressure distribution, resulting in an increased load under the midfoot and rearfoot and an increase in the variability of plantar pressure during barefoot gait. The progression of diabetic neuropathy was not found to influence plantar pressure distribution.

Effect of reduced cutaneous cues on motion perception and postural control

To investigate whether the sensory perception could be a more direct assessment of sensory deficit as oppose to the postural performance, we examined the effect of reduced cutaneous cues on motion perception and motion control. The subject was translated in a mediolateral direction with a single sinusoidal acceleration at a stimulus frequency of 0.25 Hz with a peak acceleration magnitude ranging from 0.25 to 8 mG in the dark. Two different plantar cutaneous conditions were provided: the control condition (barefoot) and the reduced cutaneous condition (foot on a spongy surface). For each foot-sole sensory condition, the subject completed six sets of 33 randomly ordered translation stimuli. After each translational stimulus, the subject reported their perceived direction of motion by pressing a hand-held button. The center of pressure (COP) and joint kinematics of the quiet stance were also measured. The results showed a significant increase in perception threshold as well as COP variation in the anteroposterior direction in the reduced cutaneous cue trials. However, a non-significant increase in COP in the mediolateral direction was shown. Multivariate covariance analysis of joint kinematics showed changes in postural coordination, such as increased reliance on hip strategy under reduced cutaneous cues condition, that have not been differentiated by univariate measures. The observed discrepancy in the significance of the contribution of plantar cutaneous cues to the detection threshold and the COP variation implies that the 'perception' could provide more direct and sensitive assessment of the sensory degradation than the 'action'.

Redistribution of joint moments is associated with changed plantar pressure in diabetic polyneuropathy

BACKGROUND

Patients with diabetic polyneuropathy (DPN) are often confronted with ulceration of foot soles. Increased plantar pressure under the forefoot has been identified as a major risk factor for ulceration. This study sets out to test the hypothesis that changes in gait characteristics induced by DPN related muscle weakness are the origin of the elevated plantar pressures.

METHODS

Three groups of subjects participated: people diagnosed with diabetes without polyneuropathy (DC), people diagnosed with diabetic polyneuropathy (DPN) and healthy, age-matched controls (HC). In all subjects isometric strength of plantar and dorsal flexors was assessed. Moreover, joint moments at ankle, knee and hip joints were determined while walking barefoot at a velocity of 1.4 m/s. Simultaneously plantar pressure patterns were measured.

RESULTS

Compared to HC-subjects, DPN-participants walked with a significantly increased internal plantar flexor moment at the first half of the stance phase. Also in DPN-subjects the maximal braking and propelling force applied to the floor was decreased. Moreover, in DPN-subjects the ratio of forefoot-to-rear foot plantar pressures was increased. Body-mass normalized strength of dorsal flexors showed a trend to be reduced in people with diabetes, both DC and DPN, compared to HC-subjects. Plantar flexors tended to be less weak in DC compared to HC and in DPN relative to DC.

CONCLUSION

The results of this study suggest that adverse plantar pressure patterns are associated with redistribution of joint moments, and a consequent reduced capacity to control forward velocity at heel strike.

Plantar pressure distribution patterns during gait in diabetic neuropathy patients with a history of foot ulcers

OBJECTIVE

To investigate and compare the influence of a previous history of foot ulcers on plantar pressure variables during gait of patients with diabetic neuropathy.

INTRODUCTION

Foot ulcers may be an indicator of worsening diabetic neuropathy. However, the behavior of plantar pressure patterns over time and during the progression of neuropathy, especially in patients who have a clinical history of foot ulcers, is still unclear.

METHODS

Subjects were divided into the following groups: control group, 20 subjects; diabetic neuropathy patients without foot ulcers, 17 subjects; and diabetic neuropathy patients with at least one healed foot ulcer within the last year, 10 subjects. Plantar pressure distribution was recorded during barefoot gait using the Pedar-X system.

RESULTS

Neuropathic subjects from both the diabetic neuropathy and DNU groups showed higher plantar pressure than control subjects. At midfoot, the peak pressure was significantly different among all groups: control group (139.4+/-76.4 kPa), diabetic neuropathy (205.3+/-118.6 kPa) and DNU (290.7+/-151.5 kPa) (p=0.008). The pressure-time integral was significantly higher in the ulcerated neuropathic groups at midfoot (CG: 37.3+/-11.4 kPa.s; DN: 43.3+/-9.1 kPa.s; DNU: 68.7+/-36.5 kPa.s; p=0.002) and rearfoot (CG: 83.3+/-21.2 kPa.s; DN: 94.9+/-29.4 kPa.s; DNU: 102.5+/-37.9 kPa.s; p=0.048).

CONCLUSION

A history of foot ulcers in the clinical history of diabetic neuropathy subjects influenced plantar pressure distribution, resulting in an increased load under the midfoot and rearfoot and an increase in the variability of plantar pressure during barefoot gait. The progression of diabetic neuropathy was not found to influence plantar pressure distribution.

Diabetes mellitus and gait dysfunction: possible explanatory factors

BACKGROUND AND OBJECTIVE

Gait characteristics differ in individuals with diabetes compared with those without diabetes. Limited information regarding potential explanatory factors for this association exists. This study examined the association between diabetes and gait characteristics in older adults and explored potential explanatory factors.

DESIGN

A cross-sectional, observational study design was used.

METHODS

At the 1998-1999 clinic visit, 558 ambulatory older adults (mean age=79 years) from the Pittsburgh site of the Cardiovascular Health Study had an assessment of their gait characteristics, diabetes, health status, cognition, mood, lower-extremity circulation and sensation, vision, lower-extremity strength (force-producing capacity), physical activity, and body mass index (BMI). A series of linear regression models were developed to examine the association between diabetes and gait characteristics and to examine potential explanatory factors for the associations.

RESULTS

Diabetes was related to gait speed (beta=-.06 m/s); however, the association was partially explained by health status variables, cognition, mood, lower-extremity circulation and sensation, visual impairment, lower-extremity strength, physical activity, and BMI. Health status and lower-extremity strength each explained the greatest proportion of the association (beta reduced 66% by each). Diabetes was related to step width (beta=.02 m), and the association could not be explained by the examined factors.

CONCLUSIONS

Diabetes was associated with gait alterations in older adults. Slowed gait speed appears to be secondary to the peripheral effect of the disease on other body systems. The effect of diabetes on step width was not explained in the analyses and may be related to peripheral motor nerve function or central influences of the disease, which could not be assessed in this study.

The effect of diabetic neuropathy and previous foot ulceration in EMG and ground reaction forces during gait

BACKGROUND

We aimed at investigating the influence of diabetic neuropathy and previous history of plantar ulcers on electromyography (EMG) of the thigh and calf and on vertical ground reaction forces during gait.

METHODS

This study involved 45 adults divided into three groups: a control group (n=16), diabetic neuropathic group (n=19) and diabetic neuropathic group with previous history of plantar ulceration (n=10). EMG of the right vastus lateralis, lateral gastrocnemius and tibialis anterior were studied during the stance phase. The peaks and time of peak occurrence were determined and a co-activation index between tibialis anterior and lateral gastrocnemius. In order to represent the effect of the changes in EMG, the first and second peaks and the minimum value of the vertical ground reaction force were also determined. Inter-group comparisons of the electromyographical and ground reaction forces variables were made using three MANCOVA (peaks and times of EMG and peaks of force) and one ANCOVA (co-activation index).

FINDINGS

The ulcerated group presented a delayed in the time of the lateral gastrocnemius and vastus lateralis peak occurrence in comparison to control's. The lateral gastrocnemius delay may be related to the lower second vertical peak in diabetic subjects. However, the delay of the vastus lateralis did not cause any significant change on the first vertical peak.

INTERPRETATIONS

The vastus lateralis and lateral gastrocnemius delay demonstrate that ulcerated diabetic neuropathic patients have a motor deficit that could compromise their ability to walk, which was partially confirmed by changes on ground reaction forces during the push-off phase.

Gait characteristics of diabetic patients: a systematic review

Patients with diabetes are at higher risk of experiencing fall-related injuries when walking than healthy controls. The underlying mechanism responsible for this is not yet clear. Thus we intend to summarize diabetic patients' gait characteristics and emphasize those which could be the possible underlying mechanisms for increased fall risk. This systematic review aims, in particular, to: (1) evaluate the quality of existing studies which investigate the gait characteristics of diabetic patients, (2) highlight areas of agreement and contradiction in study results, (3) discuss and emphasize parameters associated with fall risk, and (4) propose new orientations and further domains for research needed for their fall risk prevention. We conducted an electronic search of Pedro, PubMed, Ovid and Cochrane. Two authors independently assessed all abstracts. Quality of the selected articles was scored, and the study results summarized and discussed. We considered 236 abstracts of which 28 entered our full text review. Agreement on data quality between two reviewers was high (kappa: 0.90). Authors investigating gait parameters in a diabetic population evaluated in particular parameters either associated with fall risk (speed, step length or step-time variability) or with ulcers (pressure). There is agreement that diabetic patients walk slower, with greater step variability, and present higher plantar pressure than healthy controls. We concluded that diabetic patients present gait abnormalities, some of which can lead to heightened fall risk. To understand its' underlying mechanisms, and to promote efficient prevention, further studies should analyse gait under 'real-life' conditions.

A 1-year study of gait characteristics in diabetes: The impact of rosiglitazone

Fifty subjects diagnosed with type 2 diabetes and 30 subjects with no history of diabetes (controls) were examined to assess their gait characteristics during the initiation of gait, gait in a linear path and during turns. Gait characteristics were measured by pressure sensors in the shoes, accelerometers on the knees and the electromyogram from the medial gastrocnemius and tibialis anterior muscles.

Thirty subjects with diabetes (D1) and 20 control subjects (C) were followed for a period of 1year to see if gait changed over that period, especially in the diabetic population. Twenty additional subjects with diabetes (D2) were placed on the insulin sensitizer rosiglitazone (RSG) – a drug known to also improve vascular endothelial function – and were also followed for 1year.

The results showed that D1 had more unsteadiness in their gait; they walked more slowly and with more circumduction (lateral movement during the swing phase) than did C. D1 also showed greater muscle use and co-contraction of agonist and antagonist pairs of muscle during gait when compared to controls. While the controls showed no difference in gait over the year, D1 showed deterioration in gait and D2 showed improved gait over the 1year. Thus, diabetes seems to continually deteriorate gait unless a drug like RSG is given. When RSG was administered for 1year, the velocity of gait, circumduction and muscle use was increased to near that of the age-matched controls.

Implementing a clinical assessment protocol for sensory and skeletal function in diabetic neuropathy patients at a university hospital in Brazil

CONTEXT AND OBJECTIVE

Physiotherapy can contribute towards recovering or preventing physical and sensory alterations in diabetic neuropathy patients. Our objective was to create and apply a protocol for functional assessment of diabetic neuropathy patients' lower limbs, to guide future physiotherapy.

DESIGN AND SETTING

Clinical study at the University Hospital and teaching/research center of Universidade de São Paulo.

METHODS

An intentional sample of diabetic neuropathy patients was utilized. The protocol was divided into: (1) preliminary investigation with identification of relevant clinical diabetes and neuropathy characteristics; (2) thermal, tactile and proprioceptive sensitivity tests on the feet; (3) evaluations of muscle function, range of motion, lower limb function, foot anthropometry.

RESULTS

The patients' mean age was 57 years, and they had had the diagnosis for 13 years on average. Distal numbness and tingling/prickling were present in 62% and 67%, respectively. There were tactile sensitivity alterations above the heel in 50%, with thermal sensitivity in 40% to 60%. The worst muscle function test responses were at the triceps surae and foot intrinsic muscles. Longitudinal plantar arches were lowered in 50%. Decreased thermal and tactile sensitivity of the heels was found. There was a general reduction in range of motion.

CONCLUSIONS

The results provided detailed characterization of the patients. This protocol may be easily applied in healthcare services, since it requires little equipment, at low cost, and it is well understood by patients.

[Clinical gait analysis]

Clinical gait analysis comprises a well defined repertoire of various methods for valid and reliable assessment. The rapid development of corresponding hardware and software has substantially decreased the efforts necessary for data processing and has promoted the clinical applicability of the procedures. The clinical question defines the amount of methodological input. Clinical gait analysis may provide diagnostic insight into the pathobiomechanics and the pathophysiology of complex gait disorders for which a profound understanding of the underlying causes is a prerequisite for adequate treatment. The methods may help in the screening of gait function following reconstructive surgery as a measure of quality control, the assessment of the severity of a gait disturbance, the evaluation of a rehabilitation process, or the quantification of the effect of orthoses, insoles or specific shoe ware. Simple procedures of gait analysis may suffice to obtain information on gait function which can not be derived by mere clinical observation and which can be incorporated into a clinical concept.

Gait characteristics in people with type 2 diabetes mellitus

Sixteen control subjects and 15 subjects with type 2 diabetes were examined to compare gait characteristics during walking in a linear path and in turns of 0.33 and 0.66 m diameter. Subjects were excluded if there was diminished sensation in the feet or impairment of strength in the legs. This was done to isolate the effect of diabetes gait independent of loss of sensation. Gait was assessed through contact sensors on the foot, video, and two axis accelerometers mounted bilaterally on the head, shoulders, hips, knees and ankles. The results of these experiments showed that subjects with diabetes walked significantly slower (P<0.05) than control subjects and with a wider stance (P<0.01), both for walking in a linear path (velocity of subjects with diabetes was 62.2% that of controls and stance was 134.9% wider than controls) and when making turns (velocity 50.6% of controls and stance 120.1% wider than that of controls). Accelerometry showed increased flexion/extension and lateral movement of the major joints in subjects with diabetes during both walking in a linear path and turns compared to control subjects. Part of the increased movement at the joints in the subjects with diabetes was due to tremor in both the 8 Hz and 16 Hz bands. These findings suggest that at least some of the increased joint movement during walking in people with diabetes is likely neurological in origin and not related to muscle weakness or loss of sensation in the feet.

Reduced plantar sensation causes a cautious walking pattern

The aim of this study was to investigate the influence of reduced plantar sensation on gait patterns during walking in 20 healthy subjects (25.9 +/- years, 61.6 +/- 11.5 kg, 178 +/- 9.5 cm) with no history of sensory disorders. Force plate measurements, electromyography (EMG) measurements and a three-dimensional movement analysis were performed simultaneously during barefoot walking before and after reduction of plantar sensation using an ice immersion technique. The results show that reduced plantar sensation leads to significant changes in gait patterns that are present at the ankle, knee and hip joint and indicate a more cautious ground contact and push-off with modified EMG and motion patterns.

Plantar soft tissue loading under the medial metatarsals in the standing diabetic foot

Diabetes mellitus (type 2) is the most frequent cause of non-traumatic lower-limb amputations. The major cause of impairment to the feet of diabetics is persistent hyperglycemia, potentially leading to peripheral neuropathy as well as to pathological changes in plantar soft tissue, which stiffen its structure and diminish its ability to effectively distribute foot-ground contact loads. In this study, a computational model of the foot structure in the standing position was utilized to evaluate stress distributions in plantar soft tissue under the medial metatarsal heads of simulated diabetic versus normal feet. The model comprises five anatomic planar cross-sections in the directions of the foot rays, which were solved for internal stresses under static ankle joint reaction (300 N) and triceps surae muscle forces (150 N) using the finite element method. Tissues were assumed to be homogenous, isotropic and elastic materials, with nonlinear stress-strain relations for the ligaments, fascia and plantar tissue. The model revealed significant tension stress concentrations (90-150 KPa) in the plantar pad of the simulated diabetic forefoot: they were four times the normal maximum stress under the first metatarsal head and almost eight times the normal maximum stress under the second metatarsal head. It was shown that with increased severity of stiffening of the plantar pad, as related to glucose-exposure, peak forefoot contact stresses may rise by 38 and 50% under the first and second metatarsal heads, respectively. The increase in averaged (von Mises) internal stresses within the plantar soft tissue is even more pronounced, and may rise by 82 and 307% for the tissue under the first and second metatarsal heads, respectively. These results, which conform to experimental data gathered over the last two decades, suggest that the process of injury in diabetic feet is very likely to initiate not on the skin surface, but in deeper tissue layers, and the tissues underlying the distal bony prominences of the medial metatarsals are the most vulnerable ones.

Influence of the diabetic neuropathy on the behavior of electromyographic and sensorial responses in treadmill gait

OBJECTIVE

We describe and interpret self-cadence treadmill walking by neuropathic diabetic subjects under biomechanical and somatosensorial considerations.

DESIGN

EMG variables during stance phase of neuropathic diabetic subjects were acquired and analyzed. We also evaluated sensorial and motor aspects of the feet and legs.

METHODS

The experimental procedures are divided as follows: (a) determination of the sensitive cronaxie and pain tolerance in selected plantar areas, (b) determination and description of temporal aspects of EMG patterns of the vastus lateralis, tibialis anterior and lateral gastrocnemius of both sides during treadmill walking. We analyze and compare the results of the sensitive cronaxie, pain tolerance and the EMG parameters obtained by two experimental groups: diabetic neuropathic (n=20) and non-diabetic control subjects (n=20).

RESULTS

The somatosensorial responses and pain tolerance threshold in the diabetic neuropathic group were significantly higher and considered far from the normal patterns. The EMG responses of the thigh and leg muscles in the diabetic neuropathic group were delayed if compared to the normal recruitment pattern, especially the tibialis anterior and vastus lateralis.

CONCLUSIONS

These findings lead us to conclude that probably central and/or peripheral control mechanisms of the gait of neuropathic diabetic patients are altered due to somatosensorial and motor deficits. The mechanism of load reduction during walking was considered inefficient because of the activation delay of the vastus lateralis and tibialis anterior. We have concluded that the peripheral diabetic neuropathy damages not only somatosensorial and motor sources but also intrinsic mechanisms of motor control leading to alterations in the ankle efficiency in gait. This resulting distal inefficiency compromises some of the principal requirements for gait, such as progression and balance.

RELEVANCE

This investigation is based on an innovating thematic approach involving the diabetic peripheral neuropathy. This innovation concerns the use of EMG and an instrumented treadmill in a clinical application to study and interpret the motor control during gait in neuropathic diabetic patients.