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author:("Najafi, bilan")
1.  Motorized mobility scooters – The use of training/intervention and technology for improving driving skills in aging adults - A Mini-Review 
Gerontology  2014;60(4):357-365.
Motorized mobility scooters (MMS) have become the most acceptable powered assistive device for those with impaired mobility, who have sufficient upper body strength and dexterity, and postural stability. Although several benefits have been attributed to MMS usage, there are likewise risks of use, including injuries and even deaths.
The aim of the current review was to summarize results from clinical studies regarding the enhancement of MMS driver safety with a primary focus on improving driving skills/performance using clinical approaches. We addressed three main objectives: 1) to identify and summarize any available evidence (strong, moderate, or weak evidence based on the quality of studies) regarding improved driving skills/performance following training/intervention; 2) to identify types of driving skills/performance that might be improved by training/intervention; and 3) to identify the use of technology in improving MMS performance or training procedure.
Articles were searched for in the following medical and engineering electronic databases: PubMed, Cochrane Library, Web of Science,, PsycINFO, CINAHL, ERIC, EI Compendix, IEEE Explore, and REHABDATA. Inclusion criteria included: aging adults or those with ambulatory problems; intervention or targeted training; and clinical trial. Outcomes included: MMS skills/performance.
Six articles met the inclusion criteria and are analyzed in this review. Four of the six articles contained training approaches for MMS drivers including skill trainings using real MMS inside and outside (i.e., in community) and in a 3D virtual environment. The other two studies contain infrastructural assessments (i.e., the minimum space required for safe maneuverability of MMS users) and additional mobility assistance tools to improve maneuverability and to enhance driving performance.
Results from the current review showed improved driving skills/performance by training, infrastructural assessments, and incorporating mobility assistance tools. MMS driving skills that can be improved through driver training include: weaving, negotiating with and avoiding pedestrian interference, simultaneous reading of signs and obstacle avoidance in path, level driving, forward and reverse driving, figure 8s, turning in place, crossing left slope, maneuvering down a 2-inch curb, and driving up and down inclines. However, several limitations exist in the available literature regarding evidence of improved driving skills/performance following training/intervention, such as small sample sizes, lack of control groups and statistical analysis.
PMCID: PMC4074432  PMID: 24481257
scooter; driver safety; aging adults; training; virtual environment; intervention; assistive tools
2.  Frailty and Technology: A Systematic Review of Gait Analysis in Those with Frailty 
Gerontology  2013;60(1):79-89.
New technologies for gait assessment areemerging and have provided new avenues for accurately measuring gait characteristics in home and clinic. However, potential meaningful clinical gait parameters beyond speed have received little attention in frailty research.
To study gait characteristics in different frailty status groups for identifying the most useful parameters and assessment protocols for frailty diagnosis.
We searched PubMed, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Library, and Age Line. Articles were selected according to the following criteria: (1) population: individuals defined as frail, prefrail, or transitioning to frail, and (2) outcome measures: quantitative gait variables as obtained by biomechanical analysis. Effect sizes (d) were calculated for the ability of parameters to discriminate between different frailty status groups.
Eleven publications met inclusion criteria. Frailty definitions, gait protocols and parameters were inconsistent, which made comparison of outcomes difficult. Effect sizes were calculated only for the three studies which compared at least two different frailty status groups. Gait speed shows the highest effect size to discriminate between frailty subgroups, in particular during habitual walking (d = 0.76–6.17). Gait variability also discriminates between different frailty status groups in particular during fast walking. Prominent parameters related to prefrailty are reduced cadence (d = 1.43) and increased step width variability (d = 0.64), whereas frailty (vs. prefrail status) is characterized by reduced step length during habitual walking (d = 1.32) and increased double support during fast walking (d = 0.78). Interestingly, one study suggested that dual-task walking speed can be used to predict prospective frailty development.
Gait characteristics in people with frailty are insufficiently analyzed in the literature and represent a major area for innovation. Despite the paucity of work, current results suggest that parameters beyond speed could be helpful in identifying different categories of frailty. Increased gait variability might reflect a multisystem reduction and may be useful in identifying frailty. In addition, a demanding task such as fast walking or adding a cognitive distractor might enhance the sensitivity and specificity of frailty risk prediction and classification, and is recommended for frailty assessment using gait analysis.
PMCID: PMC4017858  PMID: 23949441
Gait; Technology; Analysis; Assessment; Measurement; Frailty; Older adults
3.  Diabetic Peripheral Neuropathy and Gait: Does Footwear Modify This Association? 
Gait-related fall risk is the leading cause of mortality among patients with diabetes, especially those older than 65 years. Deterioration in balance and loss of protective sensation in lower extremities contribute significantly to fall risk in patients with diabetic peripheral neuropathy (DPN). This study aimed to explore the impact of neuropathy and foot ulcer on gait.
We recruited 39 participants (age, 56.9 ± 8.2 years; body mass index, 29.6.3 ± 4.7 kg/m2), including 15 DPN patients without foot ulcers, 16 DPN patients with foot ulcers, and 8 healthy aged-matched controls. Patients with active foot ulcers wore an offloading device during gait examination, including removable cast walker.
Results suggest that neuropathy alters gait mainly by increasing gait initiation, gait variability (coefficient of variation of gait velocity), and double support (DS) time, while reducing knee range of motion and center of mass sway (p < .05). Interestingly, the presence of foot ulcer does not impact gait velocity (p > .1) but enhances some of the gait parameters such as gait variability and DS time.
This study demonstrates that neuropathy deteriorates gait, but the presence of foot ulcers does not alter gait parameters further than neuropathy. In addition, patients with foot ulcers demonstrated a better gait compared with DPN patients without ulcers. We speculate that offloading footwear may be enhancing the somatosensory feedback from sensate skin, thereby positively affecting gait parameters. A study with a larger sample is required to explore the effect of prescribed footwear in the DPN population in order to validate the findings of this research study.
PMCID: PMC3876356  PMID: 24124939
diabetes; foot ulcer; gait; offloading; wearable sensors
4.  Novel Wearable Technology for Assessing Spontaneous Daily Physical Activity and Risk of Falling in Older Adults with Diabetes 
As baby boomers age and their expected life span increases, there is an unprecedented need to better manage the health care of elders with diabetes who are at increased risk of falling due to diabetes complications, frailty, or other conditions. New clinical and research tools are needed to measure functioning accurately and to identify early indicators of risk of falling, thus translating into more effective and earlier intervention.
The objective of this pilot study was to validate a significant change in hardware and algorithm to track activity patterns using a single triaxial accelerometer through validation of timed up and go and standard measures of balance and gait. We recruited a convenience sample of eight older adults with diabetes and peripheral neuropathy (age, 77 ± 7 years old) who were asked to wear the sensor for imposed daytime activity performed in our gait laboratory. Subjects were stratified into risk of falling categories based on Tinetti scores. We examined the accuracy of the suggested technology for discrimination of high- versus low-risk groups.
The system was accurate in identifying the number of steps taken and walking duration (random error <5%). The proposed algorithm allowed accurate identification and stratification of those at highest risk of falling, suggesting that subjects with high risk of falling required a substantially longer duration for rising from a chair when compared with those with low risk of falling (p < .05).
Our new single triaxial accelerometer algorithm successfully tracked postural transition, allowing accurate identification of those at high risk of falling, and could be useful for intermittent or even continuous monitoring of older adults with diabetes. Other potential applications could include activity monitoring of the diabetes population with lower extremity disease and of patients undergoing surgical procedures or as an objective measure during rehabilitation.
J Diabetes Sci Technol 2013;7(5):1147–1160
PMCID: PMC3876357  PMID: 24124940
body-worn sensor; diabetes care; foot ulcer; home telemonitoring; physical activity monitoring; risk of falling; wearable technology
5.  Electrical Stimulation as an Adjunctive Treatment of Painful and Sensory Diabetic Neuropathy 
The objective of this review is to evaluate the use of electrical stimulation to treat diabetic neuropathy. Application of electrical stimulation may provide a novel treatment option for large and small fiber neuropathy in persons with diabetes. Large and small nerve neuropathy alters pain, proprioception, touch perception, and motor function, which cause burning foot pain and serve as protective mechanisms from ulcerations.
A content search for clinical trials involving electrical stimulation, neuropathy, and diabetes was conducted through PubMed. Randomized clinical trials and prospective studies with outcome measures affecting the lower extremity function were selected for review.
We identified eight studies in which electrical stimulation was used to treat diabetic neuropathy. Six studies evaluated small fiber neuropathy. Two studies evaluated patients with both small and large fiber neuropathy and reported significant improvement in vibration and monofilament testing and reduction in symptoms in the electrical stimulation treatment group. Six of the eight painful neuropathy studies identified significant improvement in symptoms. There were no studies that evaluated electrical stimulation to treated diabetic motor neuropathy, fall prevention or postural instability.
Electrical stimulation may be an effective alternative and adjunctive therapy to current interventions for diabetic peripheral neuropathy.
PMCID: PMC3876364  PMID: 24124947
diabetes; electrical stimulation; fall; infection; neuropathy; prevention; ulcer
6.  Improvements in gait characteristics after intensive resistance and functional training in people with dementia: a randomised controlled trial 
BMC Geriatrics  2014;14:73.
Preventing and rehabilitating gait disorders in people with dementia during early disease stage is of high importance for staying independent and ambulating safely. However, the evidence gathered in randomized controlled trials (RCTs) on the effectiveness of exercise training for improving spatio-temporal gait parameters in people with dementia is scarce. The aim of the present study was to determine whether a specific, standardized training regimen can improve gait characteristics in people with dementia.
Sixty-one individuals (mean age: 81.9 years) with confirmed mild to moderate stage dementia took part in a 3-month double-blinded outpatient RCT. Subjects in the intervention group (IG) received supervised, progressive resistance and functional group training for 3 months (2 times per week for two hours) specifically developed for people with dementia. Subjects in the control group (CG) conducted a low-intensity motor placebo activity program. Gait characteristics were measured before and after the intervention period using a computerized gait analysis system (GAITRite®).
Adherence to the intervention was excellent, averaging 91.9% in the IG and 94.4% in the CG. The exercise training significantly improved gait speed (P < 0.001), cadence (P = 0.002), stride length (P = 0.008), stride time (P = 0.001), and double support (P = 0.001) in the IG compared to the CG. Effect sizes were large for all gait parameters that improved significantly (Cohen’s d: 0.80-1.27). No improvements were found for step width (P = 0.999), step time variability (P = 0.425) and Walk-Ratio (P = 0.554). Interestingly, low baseline motor status, but not cognitive status, predicted positive training response (relative change in gait speed from baseline).
The intensive, dementia-adjusted training was feasible and improved clinically meaningful gait variables in people with dementia. The exercise program may represent a model for preventing and rehabilitating gait deficits in the target group. Further research is required for improving specific gait characteristics such as gait variability in people with dementia.
Trial registration
PMCID: PMC4062767  PMID: 24924703
7.  Virtualizing the Assessment: A Novel Pragmatic Paradigm to Evaluate Lower Extremity Joint Perception in Diabetes 
Gerontology  2012;58(5):463-471.
Persons with diabetes have a higher risk of falls and fall related injuries. People with diabetes often develop peripheral neuropathy (DPN) as well as nerve damage throughout the body. In particular, reduced lower extremity proprioception due to DPN may cause a misjudgment of foot position and thus increase the risk of fall.
An innovative virtual obstacle crossing (VOC) paradigm using wearable sensors was developed in attempt to assess lower extremity position perception damage due to DPN.
Sixty-seven participants (Age: 55.4±8.9; BMI: 28.1±5.8) including diabetes with and without DPN as well as aged matched healthy controls were recruited. Severity of neuropathy was quantified using vibratory perception threshold (VPT) test. The ability of perception of lower extremity was quantified by measuring obstacle crossing success rate (OCSR), toe-obstacle clearance (TOC), and reaction time (TR) while crossing a series of virtual obstacles with heights at 10% and 20% of the subject’s leg length.
No significant difference was found between groups for age and BMI. The data revealed that DPN subjects had a significantly lower OCSR compared to diabetes with no neuropathy and controls at obstacle size of 10% (p<0.05). DPN subjects also demonstrated longer TR compared to other groups and for both obstacle sizes. In addition TOC was reduced in neuropathy groups. Interestingly, a significant correlation between TR and VPT (r=0.5, p<10-5) was observed indicating delay in reaction by increasing neuropathy severity. The delay becomes more pronounced by increasing the size of obstacle. Using regression model suggests that the change in reaction time between obstacle sizes of 10% and 20% of leg size is the most sensitive predictors for neuropathy severity with an odds ratio of 2.70 (p=0.02).
The findings demonstrate proof of concept of virtual reality application as a promising method for objective assessment of neuropathy severity, however; a further study is warranted to establish a stronger relationship between the measured parameters and neuropathy.
PMCID: PMC3955209  PMID: 22572476
Virtual Reality; Diabetes Peripheral Neuropathy; Lower Extremity Joint Perception; Body Worn Sensors; Fall Prevention; Obstacle crossing
8.  Mechanism of orthotic therapy for the painful cavus foot deformity 
People who have extremely high arched feet or pes cavus often suffer from substantial foot pain. Custom-made foot orthoses (CFO) have been shown to be an effective treatment option, but their specificity is unclear. It is generally thought that one of the primary functions of CFO is redistributing abnormal plantar pressures. This study sought to identify variables associated with pain relief after CFO intervention.
Plantar pressure data from a randomized controlled trial of 154 participants with painful pes cavus were retrospectively re-analyzed at baseline and three month post CFO intervention. The participants were randomized to a treatment group given CFO or a control group given sham orthoses.
No relationship between change in pressure magnitude and change in symptoms was found in either group. However, redistribution of plantar pressure, measured with the Dynamic Plantar Loading Index, had a significant effect on pain relief (p = 0.001). Our final model predicted 73% of the variance in pain relief from CFO and consisted of initial pain level, BMI, foot alignment, and changes in both Dynamic Plantar Loading Index and pressure–time integral.
Our data suggest that a primary function of effective orthotic therapy with CFO is redistribution of abnormal plantar pressures. Results of this study add to the growing body of literature providing mechanistic support for CFO providing pain relief in painful foot conditions. The proposed model may assist in better designing and assessing orthotic therapy for pain relief in patients suffering painful cavus foot deformity.
Trial registration
Randomized controlled trial: ISRCTN84913516
PMCID: PMC3924916  PMID: 24450305
Foot pain; Pes cavus; Plantar pressure; Modeling pain relief; Probability distribution of peak pressure; Dynamic plantar loading index
9.  Electrical stimulation to accelerate wound healing 
Diabetic Foot & Ankle  2013;4:10.3402/dfa.v4i0.22081.
There are several applications of electrical stimulation described in medical literature to accelerate wound healing and improve cutaneous perfusion. This is a simple technique that could be incorporated as an adjunctive therapy in plastic surgery. The objective of this review was to evaluate the results of randomized clinical trials that use electrical stimulation for wound healing.
We identified 21 randomized clinical trials that used electrical stimulation for wound healing. We did not include five studies with treatment groups with less than eight subjects.
Electrical stimulation was associated with faster wound area reduction or a higher proportion of wounds that healed in 14 out of 16 wound randomized clinical trials. The type of electrical stimulation, waveform, and duration of therapy vary in the literature.
Electrical stimulation has been shown to accelerate wound healing and increase cutaneous perfusion in human studies. Electrical stimulation is an adjunctive therapy that is underutilized in plastic surgery and could improve flap and graft survival, accelerate postoperative recovery, and decrease necrosis following foot reconstruction.
PMCID: PMC3776323  PMID: 24049559
diabetic foot ulcer; electric stimulation therapy; treatment outcome; perfusion; infection
10.  Impact of strut height on offloading capacity of removable cast walkers 
Reducing weight-bearing stress to diabetic foot ulcers is critical to healing and commonly called offloading. Removable cast walkers are frequently used for offloading; however, patient compliance is often poor. Walkers commonly extend to the knee. Patients complain about walkers' weight and diminished balance with their use. This study compared the offloading capacity of walkers that varied by height. Heights included: knee, ankle, and shoe levels. To ensure a fair comparison the outsole and insole were standardized across the devices.
Eleven diabetic subjects with moderate to high risk of ulceration were recruited. Subjects completed four 20 m walking trials. Subjects performed one trial with each walker and one trial with an athletic shoe. Primary outcomes focused on plantar loading and were measured by pressure insoles. Secondary outcomes were associated with gait kinematics as collected by body worn sensors.
Significant differences were found for the peak pressure and pressure time integrals of the different footwear. All walkers performed better than the athletic shoe. The ankle and knee-high devices performed best. Center of mass rotation data showed a trend of the ankle walker yielding a smaller range of motion (18% medial/lateral and 22% anterior/posterior) than the knee level.
The ankle-high walker was able to provide similar offloading capacities as the knee-high walker. The diminished weight, along with potentially improved stability, may result in improved compliance with ankle-high walkers. A study comparing the use of the two devices for treating ulcers is now suggested.
PMCID: PMC3572545  PMID: 22465241
Offloading; Diabetic foot ulcer; Diabetes; Pedobarography
11.  Dynamic Plantar Loading Index: Understanding the benefit of Custom Foot Orthoses for Painful Pes Cavus 
Journal of Biomechanics  2012;45(9):1705-1711.
The purpose of this study was to evaluate a new method showing how custom foot orthoses (CFO) improve dynamics of plantar loading. The method is based on the probability distribution of peak pressure time series and is quantified using the Regression Factor (RF). RF is a least square regression slope between the experimentally observed plantar pressure magnitude probability distribution and a modeled Gaussian shape. Plantar pressure data from a randomized controlled trial of 154 participants with painful Pes Cavus were retrospectively re-analyzed. The participants were randomized to an active treatment group given CFO or a control group given sham orthoses. The location of 2nd Peak pressure as a percentage of stance time (PLoc2) and its magnitude (PM2) was also calculated. In addition, plantar pressure data were collected on 23 healthy volunteers with normal foot alignment and no foot pain. Results demonstrated Pes Cavus had a significantly lower RF than healthy participants (0.30 v. 0.51; p<10−7). PM2 was reduced in both active and control groups. However, RF and the PLoc2 were only changed in the active group (p<0.005) without any significant change in the control group (p>0.5). This study suggests that painful Pes Cavus alters the shape of probability distribution of plantar loading during walking and CFO are an effective therapeutic solution that can significantly improve it. Further use of the RF index and 2nd peak pressure location as an outcome measure for treatment of foot and ankle deformities is suggested.
PMCID: PMC3358483  PMID: 22516856
Pes Cavus; custom foot orthoses; randomized controlled trial; gait; orthotic devices; outcome assessment (health care)
13.  Safety and Efficacy of Mild Compression (18–25 mm Hg) Therapy in Patients with Diabetes and Lower Extremity Edema 
Patients with diabetes often present with lower extremity (LE) edema; however, because of concomitant peripheral arterial disease, compression therapy is generally avoided by providers in fear of compromising arterial circulation. This pilot study sought to assess whether diabetic socks with mild compression (18–25 mm Hg) can reduce LE edema in patients with diabetes without negatively impacting vascularity.
Eighteen subjects (9 males, 9 females) aged 61 ± 11 years with diabetes, LE edema, and a mean ankle–brachial index (ABI) of 1.10 ± 0.21 successfully completed this uncontrolled study. At baseline, subjects were fitted and instructed to wear the socks during all waking hours. Follow-up visits occurred weekly for four consecutive weeks. Edema was quantified through midfoot, ankle, and calf circumferences and cutaneous fluid measurements. Vascular status was tracked via ABI.
Repeated measures analysis of variance and least significant difference post hoc analyses were used for data analyses. Calf circumferences showed a statistically significant (p < .05) decrease of 1.3 ± 0.28 cm after just one week and remained significantly smaller than baseline throughout the study. Foot circumferences were significantly reduced at week 2 (−0.98 ± 0.35 cm) and remained significantly below baseline for the remainder of the study. The ankle also demonstrated a trend of circumference reduction but was not statistically significant. Cutaneous edema significantly reduced by week 3 (−3.1 ± 1.3 U) and remained so at week 4. Ankle–brachial index significantly increased (0.14 ± 0.049) at week 2 but was not significantly higher at weeks 3 or 4. No adverse events occurred during the study.
Mild compression therapy (18–25 mm Hg) decreased swelling in diabetes patients with LE edema without compromising vascularity.
PMCID: PMC3440039  PMID: 22768895
compression; diabetes; edema; lower extremity
15.  Methodology for Use of a Neuroprosthetic to Reduce Plantar Pressure: Applications in Patients with Diabetic Foot Disease 
PMCID: PMC3320844  PMID: 22401344
diabetic foot ulcers; functional electrical stimulation; neuroprosthetics; plantar pressure; wound healing
16.  Training dual-task walking in community-dwelling adults within 1 year of stroke: a protocol for a single-blind randomized controlled trial 
BMC Neurology  2012;12:129.
Community ambulation is a highly complex skill requiring the ability to adapt to increased environmental complexity and perform multiple tasks simultaneously. After stroke, individuals demonstrate a diminished ability to perform dual-tasks. Current evidence suggests that conventional rehabilitation does not adequately address gait-related dual-task impairments after stroke, which may be contributing to low levels of participation and physical inactivity in community-dwelling stroke survivors. The objective of this study is to investigate the efficacy of dual-task gait training in community-dwelling adults within 1 year of stroke. Specifically, we will compare the effects of dual-task gait training and single-task gait training on cognitive-motor interference during walking at preferred speed and at fastest comfortable speed (Aim 1), locomotor control during obstacle negotiation (Aim 2), and spontaneous physical activity (Aim 3).
This single-blind randomized controlled trial will involve 44 individuals within 12 months of stroke. Following baseline evaluation, participants will be randomly allocated to single- or dual-task gait training. Both groups will receive 12, 30-minute sessions provided one-on-one over 4–6 weeks in an outpatient therapy setting. Single-task gait training involves practice of gait activities incorporating motor relearning principles. Dual-task gait training involves an identical gait training protocol; the critical difference being that the dual-task gait training group will practice the gait activities while simultaneously performing a cognitive task for 75% of the repetitions. Blinded assessors will measure outcomes at baseline, post-intervention, and 6 months after completion of the intervention. The primary outcome measure will be dual-task effects on gait speed and cognition during unobstructed walking. Secondary outcomes include spatiotemporal and kinetic gait parameters during unobstructed single- and dual-task walking at preferred and fastest comfortable walking speeds, gait parameters during high and low obstacle crossing, spontaneous physical activity, executive function, lower extremity motor function, Timed Up and Go, balance self-efficacy, number of falls, and stroke-related disability. Hypotheses for each aim will be tested using an intention-to-treat analysis with repeated measures ANOVA design.
This trial will provide evidence to help clinicians make decisions about the types of activities to include in rehabilitation to improve dual-task walking after stroke.
Trial registration NCT01568957
PMCID: PMC3517392  PMID: 23113928
Stroke; Gait; Dual-task; Attention; Cognition; Rehabilitation; Obstacle avoidance; Participation; Physical therapy
17.  Golfing Skill Level Postural Control Differences: A Brief Report 
Golfers have better balance than their age-matched counterparts; however, it is uncertain if this persists during the swing as a function of skill level. The purpose of the study was to investigate dynamic postural control (center of mass (COM) motion) measured during different phases of the swing in golfers of varying proficiency. Eighteen healthy golfers were grouped by handicap: novice (no handicap, n = 7), intermediate (handicap 15-19, n = 7), and advanced (handicap 9-14, n = 4). Indoor testing was performed hitting 3 tee shots using a common driver. A five-camera (60 Hz) motion analysis system (9 markers) was used to extract kinematics data. There were no significant group differences in gender, age, or BMI. Advanced players had lower COM displacement with respect to address at the time of maximum arm speed (p = 0. 001) compared to intermediate (57%, p = 0.014) and novice (73%, p = 0.023). These changes persisted after COM distance and time normalization. Advanced golfers had improved COM linearity during the downswing (p < 0.001) compared to intermediate (30%, p = 0.029) and novice (51%, p < 0.001). Advanced players had decreased COM displacement at the time of maximum arm speed and a more linear COM path during the early downswing. Further study should focus on these changes during ball launch conditions.
Key pointsStudies suggest that static and dynamic balance is important in golf. However, none have investigated dynamic postural control during the golf swing in golfers of varying proficiency.Our findings suggest advanced players demonstrated improved postural control at the point of maximum arm speed when compared to less skilled players. Furthermore, center of mass acceleration in advanced players is closer to impact than less-skilled players.We observed an increased center of mass linearity of trajectory during the early downswing for advanced players over novice players. We theorized this strategy may help advanced golfers to improve the economy of COM motion during golf swing and improve the performance of the shot.
PMCID: PMC3737932  PMID: 24149353
Golf Balance; Body worn sensor; postural compensatory strategy.
18.  Plantar Temperature Response to Walking in Diabetes with and without Acute Charcot: The Charcot Activity Response Test 
Journal of Aging Research  2012;2012:140968.
Objective. Asymmetric plantar temperature differences secondary to inflammation is a hallmark for the diagnosis and treatment response of Charcot foot syndrome. However, little attention has been given to temperature response to activity. We examined dynamic changes in plantar temperature (PT) as a function of graduated walking activity to quantify thermal responses during the first 200 steps. Methods. Fifteen individuals with Acute Charcot neuroarthropathy (CN) and 17 non-CN participants with type 2 diabetes and peripheral neuropathy were recruited. All participants walked for two predefined paths of 50 and 150 steps. A thermal image was acquired at baseline after acclimatization and immediately after each walking trial. The PT response as a function of number of steps was examined using a validated wearable sensor technology. The hot spot temperature was identified by the 95th percentile of measured temperature at each anatomical region (hind/mid/forefoot). Results. During initial activity, the PT was reduced in all participants, but the temperature drop for the nonaffected foot was 1.9 times greater than the affected side in CN group (P = 0.04). Interestingly, the PT in CN was sharply increased after 50 steps for both feet, while no difference was observed in non-CN between 50 and 200 steps. Conclusions. The variability in thermal response to the graduated walking activity between Charcot and non-Charcot feet warrants future investigation to provide further insight into the correlation between thermal response and ulcer/Charcot development. This stress test may be helpful to differentiate CN and its response to treatment earlier in its course.
PMCID: PMC3413979  PMID: 22900177
19.  Importance of Time Spent Standing for Those at Risk of Diabetic Foot Ulceration 
Diabetes Care  2010;33(11):2448-2450.
Despite the high cumulative plantar stress associated with standing, previous physical activity reports of diabetic patients at risk of foot ulceration have not taken this activity into account. This study aimed to monitor spontaneous daily physical activity in diabetic peripheral neuropathy (DPN) patients and examine both walking and standing activities as important foot-loading conditions.
Thirteen DPN patients were asked to wear a body-worn sensor for 48 h. Body postures (sitting, standing, and lying) and locomotion (walking, number of steps, and postural transition) were extracted.
Patients daily spent twice as much time standing (13 ± 5%) as walking (6 ± 3%). They spent 37 ± 6% of time sitting and 44 ± 8% lying down. The average number of steps per day was 7,754 ± 4,087, and the number of walking episodes was 357 ± 167 with maximum duration of 3.9 ± 3.8 min.
The large portion of DPN patients' time spent standing with the feet loaded requires further consideration when treating and preventing foot ulcers.
PMCID: PMC2963510  PMID: 20682681
20.  Assessing Postural Control and Postural Control Strategy in Diabetes Patients Using Innovative and Wearable Technology 
Currently, diagnosis of patients with postural instability relies on a rudimentary clinical examination. This article suggests an innovative, portable, and cost-effective prototype to evaluate balance control objectively.
The proposed system uses low-cost, microelectromechanical sensor, body-worn sensors (BalanSens™) to measure the motion of ankle and hip joints in three dimensions. We also integrated resulting data into a two-link biomechanical model of the human body for estimating the two-dimensional sway of the center of mass (COM) in anterior–posterior (AP) and medial–lateral (ML) directions. A new reciprocal compensatory index (RCI) was defined to quantify postural compensatory strategy (PCS) performance. To validate the accuracy of our algorithms in assessing balance, we investigated the two-dimensional sway of COM and RCI in 21 healthy subjects and 17 patients with diabetic peripheral neuropathic (DPN) complications using the system just explained. Two different conditions were examined: eyes open (EO) and eyes closed (EC) for duration of at least 30 seconds. Results were compared with center of pressure sway (COP) as measured by a pressure platform (Emed-x system, Novel Inc., Germany). To further investigate the contribution of the somatosensory (SOM) feedback to balance control, healthy subjects performed EO and EC trials while standing on both a rigid and a foam surface.
A relatively high correlation was observed between COM measured using BalanSens and COP measured using the pressure platform (r = 0.92). Results demonstrated that DPN patients exhibit significantly greater COM sway than healthy subjects for both EO and EC conditions (p < 0.005). The difference becomes highly pronounced while eyes are closed (197 ± 44 cm2 vs 68 ± 56 cm2). Furthermore, results showed that PCS assessed using RCI is significantly better in healthy subjects compared to DPN subjects for both EO and EC conditions, as well as in both ML and AP directions (p < 0.05). Alteration in SOM feedback in healthy subjects resulted in diminished RCI values that were similar to those seen in DPN subjects (p > 0.05).
This study suggested an innovative system that enables the investigation of COM as well as postural control compensatory strategy in humans. Results suggest that neuropathy significantly impacts PCS.
PMCID: PMC2909506  PMID: 20663438
balance; body-worn sensor; diabetic peripheral neuropathy; postural compensatory strategy; sensory feedback
21.  Diabetic Foot Biomechanics and Gait Dysfunction 
Diabetic foot complications represent significant morbidity and precede most of the lower extremity amputations performed. Peripheral neuropathy is a frequent complication of diabetes shown to affect gait. Glycosylation of soft tissues can also affect gait. The purpose of this review article is to highlight the changes in gait for persons with diabetes and highlight the effects of glycosylation on soft tissues at the foot–ground interface.
PubMed, the Cochrane Library, and EBSCOhost® on-line databases were searched for articles pertaining to diabetes and gait. Bibliographies from relevant manuscripts were also searched.
Patients with diabetes frequently exhibit a conservative gait strategy where there is slower walking speed, wider base of gait, and prolonged double support time. Glycosylation affects are observed in the lower extremities. Initially, skin thickness decreases and skin hardness increases; tendons thicken; muscles atrophy and exhibit activation delays; bones become less dense; joints have limited mobility; and fat pads are less thick, demonstrate fibrotic atrophy, migrate distally, and may be stiffer.
In conclusion, there do appear to be gait changes in patients with diabetes. These changes, coupled with local soft tissue changes from advanced glycosylated end products, also alter a patient’s gait, putting them at risk of foot ulceration. Better elucidation of these changes throughout the entire spectrum of diabetes disease can help design better treatments and potentially reduce the unnecessarily high prevalence of foot ulcers and amputation.
PMCID: PMC2909514  PMID: 20663446
biomechanics; diabetes; foot
22.  Does footwear type impact the number of steps required to reach gait steady-state?: An innovative look at the impact of foot-orthoses on gait initiation 
Gait & posture  2010;32(1):29-33.
Many studies have attempted to better elucidate the effect of foot orthoses on gait dynamics. To our knowledge, most previous studies exclude the first few steps of gait and begin analysis at steady-state walking. These unanalyzed steps of gait may contain important information about the dynamic and complex processes required to achieve equilibrium for a given gait velocity. The purpose of this study was to quantify gait initiation and determine how many steps were required to reach steady state walking under three footwear conditions: barefoot, habitual shoes, and habitual shoes with a prefabricated foot orthoses. Fifteen healthy subjects walked 50 meters at habitual speed in each condition. Wearing habitual shoes with the prefabricated orthoses enabled subjects to reach steady state walking in fewer steps (3.5 steps ± 2.0) compared to the barefoot condition (5.2 steps ± 3.0; p=0.02) as well as compared to the habitual shoes condition (4.7 steps ± 1.6; p=0.05). Interestingly, the subjects’ dynamic medial-lateral balance was significantly improved (22%, p<0.05) by using foot orthoses compared to other footwear conditions. These findings suggest that foot orthoses may help individuals reach steady state more quickly and with a better dynamic balance in the medial-lateral direction, independent of foot type. The findings of this pilot study may open new avenues for objectively assessing the impact of prescription footwear on dynamic balance and spatio-temporal parameters of gait. Further work to better assess the impact of foot orthoses on gait initiation in patients suffering from gait and instability pathologies may be warranted.
PMCID: PMC2891407  PMID: 20362453
gait; orthotic devices; outcome assessment (health care)

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