Leg Function Research Articles

A Lower Leg Physical Activity Intervention for Individuals With Chronic Venous Leg Ulcers: Randomized Controlled Trial.

BackgroundIndividuals with venous leg ulcers (VLUs) suffer disproportionately with multiple chronic conditions, are often physically deconditioned, and demonstrate high levels of physical inactivity.ObjectiveThe primary objective of this randomized controlled trial was to establish the feasibility of a mobile health (mHealth) physical activity exercise app for individuals with VLUs to improve lower leg function.MethodsIn a 6-week study, adults with VLUs were recruited from 2 wound centers in South Carolina, United States, and enrolled if they were aged 18 years or older with impaired functional mobility and an ankle-brachial index between 0.8 and 1.3. Participants were randomized 1:1 to receive evidence-based, phased, nonexertive physical conditioning activities for lower leg function (FOOTFIT) or FOOTFIT+ with an added patient-provider communication feature. The mHealth Conditioning Activities for Lower Leg Function app also provided automated educational and motivational messages and user reports. Foot movement on the VLU-affected leg was tracked by a Bluetooth-enabled triaxial accelerometer. The study was guided by the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework to assess the feasibility of reach, adherence, acceptability, implementation, and maintenance.ResultsA total of 24 patients were recruited, enrolled, and randomized in the study. Most patients reported difficulty following the protocol for exercising and using the accelerometer and mobile phone and did not use the provider contact feature. However, all patients were adherent to the 6-week exercise program more than 85% of the time for duration, whereas 33% (8/24) of patients adhered more than 85% for the frequency of performing the exercises. Across the three exercise levels, adherence did not differ between the two groups. Confidence limits around the difference in proportions ranged from −0.4 to 0.7. Providers in FOOTFIT+ were inconsistent in checking participant progress reports because of lack of time from competing work commitments. The technology became outdated quickly, making maintenance problematic. Participants said they would continue to exercise their foot and legs and liked being able to follow along with the demonstrations of each level of exercise provided through the app.ConclusionsThe findings of this study suggest that despite initial interest in using the app, several components of the program as originally designed had limited acceptability and feasibility. Future refinements should include the use of more modern technology including smaller wearable accelerometers, mobile phones or tablets with larger screens, an app designed with larger graphics, automated reporting for providers, and more engaging user features.Trial RegistrationClinicalTrials.gov NTC02632695; https://clinicaltrials.gov/ct2/show/NCT02632695

Countering disuse atrophy in older adults with low-volume leucine supplementation.

Older adults are at increased risk of being bedridden and experiencing negative health outcomes including the loss of muscle tissue and functional capacity. We hypothesized that supplementing daily meals with a small quantity (3-4 g/meal) of leucine would partially preserve lean leg mass and function of older adults during bed rest. During a 7-day bed rest protocol, followed by 5 days of inpatient rehabilitation, healthy older men and women (67.8 ± 1.1 yr, 14 men; 6 women) were randomized to receive isoenergetic meals supplemented with leucine (LEU, 0.06 g/kg/meal; n = 10) or an alanine control (CON, 0.06 g/kg/meal; n = 10). Outcomes were assessed at baseline, following bed rest, and after rehabilitation. Body composition was measured by dual-energy X-ray absorptiometry. Functional capacity was assessed by knee extensor isokinetic and isometric dynamometry, peak aerobic capacity, and the short physical performance battery. Muscle fiber type, cross-sectional area, signaling protein expression levels, and single fiber characteristics were determined from biopsies of the vastus lateralis. Leucine supplementation reduced the loss of leg lean mass during bed rest (LEU vs. CON: -423 vs. -1035 ± 143 g; P = 0.008) but had limited impact on strength or endurance-based functional outcomes. Similarly, leucine had no effect on markers of anabolic signaling and protein degradation during bed rest or rehabilitation. In conclusion, providing older adults with supplemental leucine has minimal impact on total energy or protein consumption and has the potential to partially counter some, but not all, of the negative effects of inactivity on muscle health.NEW & NOTEWORTHY Skeletal muscle morphology and function in older adults was significantly compromised by 7 days of disuse. Leucine supplementation partially countered the loss of lean leg mass but did not preserve muscle function or positively impact changes at the muscle fiber level associated with bed rest or rehabilitation. Of note, our data support a relationship between myonuclear content and adaptations to muscle atrophy at the whole limb and single fiber level.

Low leg compliance permits grounded running at speeds where the inverted pendulum model gets airborne

Animals typically switch from grounded (no flight phases) to aerial running at dimensionless speeds u^ < 1. But some birds use grounded running far above u^ = 1, which puzzles biologists because the inverted pendulum becomes airborne at this speed. Here, we combine computer experiments using the spring-mass model with locomotion data from small birds, macaques and humans to understand the relationship between leg function (stiffness, angle of attack), locomotion speed and gait. With our model, we found three-humped ground reaction force profiles for slow grounded running speeds. The minimal single-humped grounded running speed is u^ = 0.4. This speed value roughly coincides with the transition speed from vaulting to bouncing mechanics in bipeds. Maximal grounded running speed in the model is not limited. In experiments, animals changed from grounded to aerial running at dimensionless contact time around 1. Considering these real-world contact times reduces the solution space drastically, but experimental data fit well. The model still predicts maximal grounded running speed u^ > 1 for low stiffness values used by birds but decreases below u^ = 1 for increasing stiffness. For stiffer legs used in human walking and running, periodic grounded running vanishes. At speeds at which birds and macaques change to aerial running, we found periodic aerial running to intersect grounded running. This could explain why animals can alternate between grounded and aerial running at the same speed and identical leg parameters. Compliant legs enable different gaits and speeds with similar leg parameters, stiff legs require parameter adaptations.

Importance of the Rear and Non-dominant Leg in Supporting the Body in Tandem Stance

Objective: Some studies have reported that postural assessment of a narrow base of support such as the tandem stance is useful in evaluating the risk of falls. The purpose of the present study was to obtain maximum inter-foot distance (IFD) during crossover movement of the rear foot from tandem stance, and to compare these data with those of our previous study of the front leg moving across the front of the body. Methods: Forty healthy young people were recruited as subjects (aged 29 ± 6 years, 19 men). The subjects moved their rear leg across the rear of their body according to split treadmill belt movement. Maximum IFD was measured by a three-dimensional motion analysis system and defined as the largest IFD such that either foot could be removed from the treadmill belt while maintaining a standing posture. Four conditions were set for the measurements: the rear leg was dominant and non-dominant under two treadmill belt velocities (0.5 km/h and 1.0 km/h). Two-way analysis of variance was used for the analysis. Results: Normalized maximum IFD (NMIFD) was 8-9% of subject height. Interaction between the rear leg and treadmill belt velocity was not significant. There was no significant main effect of treadmill belt velocity and the dominant foot on NMIFD. Comparing the results of our previous study, under the condition of the dominant foot moving, the NMIFD of the front leg moving across the front of the body was significantly larger than that of the rear leg moving across the rear of the body. Conclusion: The function of the rear leg is important as a support under the condition of crossing the legs from a standing posture such as tandem stance.

Transplantation of free fibula composite tissue flap to repair bone and soft tissue defect after open fracture of proximal tibial

Objective To explore the clinical application and effect of free fibula composite tissue flap trans-plantation to repair bone and soft tissue defect after open fracture of proximal tibial. Methods From June, 2012 to June, 2018, free fibula composite tissue flap transplantations were applied to repair bone and soft tissue defect after open fracture of proximal tibial in 11 cases. Of the 11 cases, there were 10 males and 1 female(their ages ranged from 32 to 56, 36 on average); Six cases were caused by traffic accident, and 5 by crash. There were 3 fresh wounds and 8 chronic and infective wounds. Free fibular flaps were used in 7 cases, and free fibular flexor hallucis myocutaneous flaps were used in 4 cases. The fibular length with transplantation was 7-18 cm. The area of flaps or muscle flaps was ranged from 4 cm×8 cm to 8 cm×20 cm. Bone fracture healing was observed at 3, 6 and 12 months after operation. The function of injured extremity was evaluated in 1 year after surgical operation. Results All were successfully repaired, and composite tissue flaps survived. Of which, 10 wounds healed by first intention, and 1 wound healed by secondary intention, with the healing time of 12-18 days. All 11 cases were followed-up. The mean followed-up time was 18 months. The bone healing time ranged from 6 to 9 months (7 months on average). The Enneking Score System was applied to evaluate the leg function. Of the 11 cases, the mean scores was 25 (ranged from 22 to 27). The donor sites were not found malfunctional. Conclusion Transplantation of free fibula composite tissue flap can reduce the treatment time with good mechanical strength. It is an ideal method to repair bone and soft tissue defect after open fracture of proximal tibial. Key words: Fibula composite tissue flap; Fracture of tibial; Open fracture; Microsurgical technique

Comparative Evaluation The Role of Venous and Peritoneal Autograft as Bioscaffold for Repairing Achilles Tendon Defect in Dogs

The study was conducted on eighteen healthy dogs, which were allocated into three equal groups (six dogs each). In the first treatment, the hind limbs were prepared at the calcaneus region where Achilles’ tendon was sharply incised, sutured with Kessler method, and immobilized with gypsona. The second treatment included the using of a peritoneum graft, while the third treatment utilized the venous autograft. Following surgery, all animals were inspected clinically, grossly and histopathologically for two months. Results of the first treatment exhibited adhesion and inflammatory reaction after one and two months of surgery. Histopathological examination revealed the organization of collagen fibers and mild inflammatory reaction after two months of surgery. The second treatment exhibited complete healing and the animal showed normal activities without any impairment on leg function. Grossly, a mild degree of adhesion was determined after two months of surgery. Histopathological examination exhibited complete granulation tissue formation with the slightest degree of fibroblast formation at 60 days. In the third treatment, there was an inflammatory reaction with moderate adhesion at one month of surgery. However, after 60 days post operation, the tendon restored the normal anatomical feature. In conclusion, unlike other treatments, results obtained from the using of peritoneal graft for reconstruction tendon defect was with the most convincing and efficient outcomes. The findings reported here shed a new light on treating of the defective tendon.

Functional measurement post-stroke via mobile application and body-worn sensor technology.

Long-term management of individuals post-stroke is essential due to the resultant chronic disability and risk for recurrent stroke. Mobile health technology shows increasing promise to provide cost-effective monitoring and support systems for the patient, caregiver, and healthcare team. Ideally, such systems will include stroke management adherence support, mechanisms to link patients and caregivers to resources, and secure longitudinal data collection with archive that are employed to optimize recovery. However, healthcare providers and computer science application developers must first collaborate to identify meaningful measures and develop methods to reliably gather such data remotely via mobile systems. mStroke is a mobile health system composed of two sensors and a mobile application designed to support optimal recovery for stroke survivors. Using the World Health Organization's International Classification of Functioning, Disability and Health model (ICF model), the authors identified 4 measures that are commonly used in the clinic and developed the mobile application features to support remote data collection: National Institutes of Health Stroke Scale (NIHSS) items 5 and 6 (Motor Arm and Leg function), Functional Reach Test (FRT), and 10 Meter Walk Test (10MWT). At a local inpatient rehabilitation facility, each measure was executed with 35 stroke survivors through simultaneous scoring by the mStroke system and standardized clinical assessment. Correlation coefficients were calculated for clinician versus mStroke system scoring. All four clinical measures significantly correlated with mStroke system app scoring: NIHSS Motor Arm-0.839, P<0.001; NIHSS Motor Leg-0.736, P<0.001; FRT-0.630, P<0.01; 10MWT-0.994, P<0.001. Results should be approached with caution as significant data skew was present for NIHSS Motor Arm and Motor Leg tests and the FRT results are not strong enough for broad translation. However, positive findings were demonstrated that support further investment in development, refinement, and testing of mobile health systems to provide clinically meaningful remote measurement via mobile technology. The ICF model was a helpful framework for guiding clinician and application developer collaboration and identifying meaningful features for app development.

Patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases

BackgroundPatient satisfaction is infrequently investigated despite its importance in assessing efficacy and patient comprehension. The purpose of this study was to investigate patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases and to evaluate how health‐related quality of life (HRQOL) is related to patient satisfaction.MethodsPatients with spinal metastases treated with surgery and/or radiotherapy were enrolled in a prospective, international, observational study. Demographic, histologic, treatment, and HRQOL data were collected. HRQOL was evaluated with the Numeric Rating Scale pain score, the 3‐level version of the EuroQol 5‐Dimension (EQ‐5D‐3L) instrument, and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0). Patient satisfaction was derived from the SOSGOQ2.0 at 6, 12, and 26 weeks after treatment. Patients were classified as satisfied, neutral, or dissatisfied.ResultsTwelve weeks after treatment, 183 of the surgically treated patients (84%) were satisfied, and only 11 (5%) were dissatisfied; in contrast, 101 of the patients treated with radiotherapy alone (77%) were satisfied, and only 7 (5%) were dissatisfied. Significant improvements in pain, physical function, mental health, social function, leg function, and EQ‐5D were associated with satisfaction after surgery. Satisfaction after radiotherapy was associated with significant improvements in pain, mental health, and overall SOSGOQ2.0 scores. Dissatisfaction after treatment was associated with lower baseline values for leg strength and lower social functioning scores for surgically treated patients and with lower social functioning scores and being single for patients treated with radiotherapy.ConclusionsHigh levels of satisfaction with treatment outcomes are observed after surgery and/or radiotherapy for spinal metastases. Posttreatment satisfaction is associated with significant improvements in pain and different dimensions of HRQOL.

Impaired Motor Function in the Affected Arm Predicts Impaired Postural Balance After Stroke: A Cross Sectional Study.

Background: Impaired postural balance is a common symptom after stroke and a common cause of falling. Most common daily tasks use arm and hand movements. Impairment in an upper extremity is a common stroke symptom, affecting 50–80% in the acute phase after stroke, and 40–50% in the sub-acute phase. The impact of leg function on postural balance has been investigated in several studies, but few have stressed the importance of arm function on postural balance.Objective: To explore whether there is any association between arm function and postural balance after stroke.Method: A cross sectional study where 121 adults (mean age: 70 ± 12.3 years, 72 men) from two different data sources, Gothenburg Very Early Supported Discharge (GOTVED), and a study by Carvalho et al. were merged. Time for assessments ranged from 1 to 13 years when the patients were in the chronic phase. The dependent variables were Berg Balance scale (BBS) and Time Up and Go (TUG) both dichotomized to “impaired postural balance” and “not impaired postural balance.” As independent variables, the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) scale was used. The FMA-UE was presented with the total score.Results: The motor function in the arm affected after stroke onset correlated with postural balance both measured with the BBS (0.321, p < 0.001) and the TUG (−0.315, p = 0.001). Having impaired motor function in the arm was significantly associated with impaired postural balance assessed with the BBS with OR = 0.879 (CI 0.826–0.934, p < 0.001). Regression analysis with the TUG showed the same result, OR = 0.868 (CI 0.813–0.927, p < 0.001) for FM-UE.Conclusion: The motor function of the affected arm was significantly associated with impaired postural balance post stroke, as assessed by BBS or TUG. It could be of clinical importance to be aware of the fact that not only lower extremity impairment, but also arm function can have an impact on postural balance in a late stage after stroke.Trial Registration: VGFOUGSB-669501.

Combined Ankle/Knee Stretching and Pivoting Stepping Training for Children With Cerebral Palsy.

After the SS-POINT program, subjects with CP showed reduced knee stiffness and intoeing angle, and improvements in both joint and leg functions in terms of ankle and knee active range of motion, ankle dorsiflexor strength, proprioception, walking speed, balance, and minimum pivoting angle. Furthermore, improvements in proprioceptive acuity and minimum pivoting angle after the SS-POINT were greater than those after the POINT. The SS-POINT approach can be used as a subject-specific training program for improving leg and walking functions and reducing intoeing during gait. This approach can serve as an individualized intervention at the joint and walking levels to maximize intervention effects by adjusting training targets, sequences, and intensities to meet the individual needs of children with CP.

Multilevel Humanlike Motion Planning for Mobile Robots in Complex Indoor Environments

In this paper, a multilevel humanlike motion planning approach is proposed for indoor mobile robots. Compared with existing approaches, the novelty of this paper is twofold: 1) the proposed path planning framework is multilevel and humanlike to ensure both foreseeability and flexibility , wherein functions of human brain, eyes, and legs are corresponding to global path planning, sensor-level path planning, and action-level path planning, respectively, and 2) along the planned path, a new velocity-adjustable trajectory planning algorithm is put forward which is provably complete and time optimal considering multiple constraints from both the robot and the environment. Experimental results show that the proposed approach has a better performance in terms of efficiency, smoothness, foreseeability, and flexibility, and autonomous navigation is realized in large-scale, dynamic, partially unknown, and unstructured indoor environments. Note to Practitioners —This paper was motivated by the motion planning problem for mobile robots in complex indoor environments. Existing approaches generally implement a two-level planning scheme, namely, global path planning and local trajectory planning. This paper proposes a novel multilevel humanlike motion planning approach, which is able to guarantee efficiency, smoothness, foreseeability, and flexibility in the presence of kinematic and environmental constraints. Experimental results show that autonomous navigation with the proposed approach is realized in large-scale, dynamic, partially unknown, and unstructured indoor environments, but human motion prediction has not yet been incorporated. In the future research, we will concentrate on human–robot interaction and environment-adaptive planning.

Leucine Supplementation Partially Protects Leg Lean Mass in Older Adults During Seven Days of Bed Rest (OR18-02-19)

ObjectivesOlder adults are at increased risk of being hospitalized or bedridden and experiencing a host of negative health outcomes including loss of lean body mass. We hypothesized that supplementing daily meals with a small quantity (3–4 g/meal) of leucine will partially preserve lean leg mass and function during bed rest. MethodsMen and women (67.8 ± 1.1 y) were randomized to receive isoenergentic meals supplemented with leucine (LEU, 0.06 g/kg/meal; n = 10) or an alanine control, (CON, 0.06 g/kg/meal; n = 10). Subjects were admitted to the Clinical Research Center for 7 days of bed rest followed by 7 days of rehabilitation. Muscle fiber type and cross-sectional area (CSA) as well as single fiber characteristics were assessed from biopsies of the vastus lateralis obtained prior to (Pre-BR) and after bed rest (Post-BR) and after rehabilitation (Post-RE). Body composition measured using iDEXA was also determined at the same time points. ResultsLeucine-supplementation partially protected leg lean mass during bed rest (–1035 vs. –423 ± 143 g; P = 0.008). Leg lean mass did not differ between the groups Post-RE (P = 0.16). There was no significant effect of time (P = 0.16) or treatment (P = 0.92) on muscle fiber CSA; however, CON subjects, but not LEU subjects, exhibited an increased number of smaller fibers (<2000 um) and fewer larger fibers (>6000 um) Post-BR. Additionally, CON subjects tended to have a greater decrement in fiber width (P = 0.085) that did not return to baseline following rehabilitation. ConclusionsSupplementing older adults with moderate amounts of leucine has the potential to partially negate some of the deleterious effects on muscle health during short bouts of inactivity. Funding SourcesNational Institutes of Health, The Claude D. Pepper Older Americans Independence Center, Sealy Center on Aging and Institute for Translational Sciences-Clinical Research Center.

Altered accelerator pedal control in a driving simulator in people with diabetic peripheral neuropathy.

AimTo investigate whether the sensory‐motor impairment attributable to diabetic peripheral neuropathy would affect control of the accelerator pedal during a driving simulator task.MethodsA total of 32 active drivers, 11 with diabetic peripheral neuropathy (mean ± sd age 67±5.0 years), 10 with diabetes but no neuropathy (diabetes group; mean ± sd age 62±10 years), and 11 healthy individuals without diabetes (healthy group; mean ± sd age 60±11 years), undertook a test on a dynamometer to assess ankle plantar flexor muscle strength and ankle joint proprioception function of the right leg, in addition to a driving simulator task. The following variables were measured: maximal ankle plantar flexor muscle strength; speed of strength generation (Nm/s); and ankle joint proprioception (ankle repositioning error, degrees). In the driving simulator task, driving speed (mph), accelerator pedal signal (degrees) and the duration of specific ‘loss‐of‐control events’ (s) were measured during two drives (Drive 1, Drive 2).ResultsParticipants with diabetic peripheral neuropathy had a lower speed of strength generation (P<0.001), lower maximal ankle plantar flexor muscle strength (P<0.001) and impaired ankle proprioception (P=0.034) compared to healthy participants. The diabetic peripheral neuropathy group drove more slowly compared with the healthy group (Drive 1 P=0.048; Drive 2 P=0.042) and showed marked differences in the use of the accelerator pedal compared to both the diabetes group (P=0.010) and the healthy group (P=0.002). Participants with diabetic peripheral neuropathy had the longest duration of loss‐of‐control events, but after one drive, this was greatly reduced (P=0.023).ConclusionsMuscle function, ankle proprioception and accelerator pedal control are all affected in people with diabetic peripheral neuropathy, adversely influencing driving performance, but potential for improvement with targeted practice remains possible.

Knee Arthrodesis After Failed Total Knee Arthroplasty.

➢ Knee arthrodesis after failure of a total knee arthroplasty (TKA) because of periprosthetic joint infection (PJI) may provide superior functional outcome and ambulatory status compared with above-the-knee amputation.➢ The use of an intramedullary nail (IMN) for knee arthrodesis following removal of TKA components because of a PJI may result in higher fusion rates compared with external fixation devices.➢ The emerging role of the antibiotic cement-coated interlocking IMN may expand the indications to achieve knee fusion in a single-stage intervention.➢ Massive bone defects after failure of an infected TKA can be managed with various surgical strategies in a single-stage intervention to preserve leg length and function.

The Multiple Sclerosis Functional Composite and Symbol Digit Modalities Test as outcome measures in pediatric multiple sclerosis.

BackgroundThere is an increasing number of pediatric multiple sclerosis (MS) clinical trials occurring; however, data validating outcome metrics that accurately capture functional disability within pediatric cohorts are limited.ObjectiveThe aim of this study was to investigate the ability of the MS Functional Composite (MSFC) and Symbol Digit Modalities Test (SDMT) to distinguish functional disability in pediatric MS patients.MethodsA total of 20 pediatric MS patients and 40 age and sex-matched controls completed the SDMT and MSFC components: a timed 25-foot walk (T25FW); 9-hole peg test (9HPT); and paced auditory serial addition test (PASAT). Z scores for MS patients were created for each test based on control means. MS patients underwent Expanded Disability Status Scale (EDSS) examination.ResultsPediatric MS patients exhibited low levels of disability on EDSS, median [range]: 1.5 [1.0–3.0]. Compared with controls, MS patients performed significantly lower on SDMT (p = 0.0002) and all MSFC components: T25FW (p = 0.001), 9HPT (p = 0.01), and PASAT (p = 0.004). SDMT and MSFC performance were not correlated with EDSS.ConclusionsDespite low levels of neurologic disability as measured by EDSS, pediatric patients with MS exhibit impaired performance in leg function, upper limb fine motor function, and auditory/visuospatial processing speeds, supporting the value of the MSFC and SDMT in this population. Longitudinal studies are needed to further validate their utility.

Design, Development, and Validation of a Lightweight Nonbackdrivable Robotic Ankle Prosthesis

Robotic ankle prostheses can imitate the biomechanical function of intact legs at the cost of a larger weight and size compared to conventional passive prostheses. Unfortunately, increased weight and size negatively affect comfort and socket stability, ultimately limiting their clinical viability. Alternatively, a nonbackdrivable transmission system can be used to actively regulate the ankle position during nonweight bearing activities only. This semiactive design can be made smaller and lighter as a result of the lower actuation power requirements. However, the transmission system must withstand high loads during stance and standing. Thus, available semiactive prostheses are still significantly heavier and have a larger build height than passive ankle prostheses. In this paper, we present the design, development, and validation of a semiactive ankle prosthesis with a nonbackdrivable cam-follower mechanism designed to lower the load on moving components and align with the foot longitudinally as necessary to reduce the prosthesis weight and size. The proposed ankle mechanism is ∼50% shorter, has ∼40% wider range of motion (ROM), and is estimated to be ∼27% lighter than available semiactive prostheses. Experiments with a transtibial subject show that the semiactive prosthesis can increase foot clearance up to 142% and reduce the load on the residual limb as low as 32% compared to passive prostheses.

Impaired Post‐Occlusive Reoxygenation and Reperfusion in the Lower Legs of PAD Patients

Peripheral arterial disease (PAD) is a systemic atherosclerotic vascular disease that leads to demand ischemia and impaired mitochondrial function in the lower legs. Identifying the extent of non‐exercise related convective and diffusive oxygen transport impairments is important in furthering our understanding of microvascular impairments in this population.PurposeThe aim of this study was to determine the extent of reperfusion and reoxygenation impairments in the medial gastrocnemius (MG) and soleus (SOL) muscles of PAD patients.MethodsA novel functional MRI (fMRI) sequence was employed to simultaneously assess tissue perfusion, T2* relaxation time (used as an index of tissue oxygenation), and venous oxygen saturation (SvO2) in 3 patients with symptomatic PAD and 3 healthy age‐matched controls. Collecting these three parameters in a single scan was achieved by interleaving a gradient‐recalled‐echo (GRE) sequence into the post‐labeling‐delay of a pulsed‐arterial‐spin‐labeling sequence (total acquisition time of about 3.2 seconds). FMRI data were continuously collected during a reactive hyperemia protocol that consisted of a 2‐minute baseline, a 5‐minute period of occlusion, and a 5‐minute period of reactive hyperemia. Occlusion pressures ranged between 185 mmHg and 200 mmHg as tolerated by the subjects. Complete occlusion was verified in all subjects. Region of interest analyses were performed on the MG and SOL muscles of each subject. Perfusion and T2* were first converted to a delta score (AU), and then analyzed for peak responses (relative to baseline), time‐to‐peak (TTP, relative to end‐occlusion), and the slope of recovery. SvO2, expressed as a percentage of oxygen (%), responds in a biphasic pattern to reactive hyperemia. Specifically, SvO2 initially decreases (termed “washout”) upon cuff release, followed by a recovery that often surpasses baseline values. Accordingly, the peaks and slopes of washout and recovery are reported for SvO2. All variables were compared between groups using independent samples t‐tests.ResultsResults indicated that MG T2* TTP was longer (+40.5±11.1 seconds, t=−3.6, P=0.02), SOL peak perfusion was attenuated (−98.9±29.5 AU, t=3.3, P=0.02), and the slope of SvO2 washout was less steep in PAD patients compared to controls (−1.3±0.3, t=3.4, P=0.02). PAD patients also tended to exhibit a longer MG T2* recovery slope (0.07±0.02, t=2.6, P=0.057), and lower MG peak perfusion (−26.0±9.8 AU, t=2.6, P=0.057) compared to controls.ConclusionsThese data suggest that reperfusion and oxygenation responses to post‐occlusive reactive hyperemia are blunted and delayed in lower legs of PAD patients. More importantly, this highlights the severity of microvascular dysfunction in this population.Support or Funding InformationThis research was supported NIH P01 HL134609 (PI‐Sinoway).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Exploratory MRI measures after intravenous autologous culture-expanded mesenchymal stem cell transplantation in multiple sclerosis.

BackgroundMesenchymal stem cells (MSC) have immunomodulatory and neuro-protective properties and are being studied for treatment of multiple sclerosis (MS). Tractography-based diffusion tensor imaging (DTI), cortical thickness (Cth) and T2 lesion volume (T2LV) can provide insight into treatment effects.ObjectiveThe objective of this study was to analyse the effects of MSC transplantation in MS on exploratory MRI measures.MethodsMRIs were obtained from 24 MS patients from a phase 1 open-label study of autologous MSC transplantation. DTI metrics were obtained in lesions and normal-appearing white matter motor tracts (NAWM). T2LV and Cth were derived. Longitudinal evolution of MRI outcomes were modelled using linear mixed effects. Pearson’s correlation was calculated between MRI and clinical measures.ResultsLesional radial diffusivity (RD) and axial diffusivity (AD) decreased pre-transplant and showed no changes post-transplant. There were mixed trends in NAWM RD and AD pre/post-transplant. Transplantation stabilized T2LV growth. NAWM RD and AD correlated with Cth, T2LV and with leg and arm function but not with cognition. Lesional DTI demonstrated similar but less robust correlations.ConclusionsMicrostructural tissue integrity is altered in MS. DTI changes pre-transplant may be influenced by concomitant lesion accrual. Contributor to DTI stabilization post-transplant is multifactorial. DTI of major motor tracts correlated well with clinical measures, highlighting its sensitivity to clinically meaningful changes.

Surgical versus Conservative Management of Lumbar Canal Stenosis in Elderly

Background: Degenerative lumbar spinal stenosis is one of the common diseases in elderly, also may occur in younger ages. Usually presents with back pain, lower limbs pain and claudication pain. Diagnosis is confirmed by radiological studies such as plain X rays LSS, CT. LSS or MRI LSS. Objective: The aim of this prospective study was to evaluate the surgical versus conservative management of lumbar canal stenosis in old patient (age of 60 years old or more). Methods: A prospective comparative study was conducted on 100 old patients that were divide into two groups, each group 50 patients. The first 50 patients underwent surgical lumbar canal decompression and the other 50 patients underwent conservative management. Results: This study showed that elderly patients with moderate to severe lumbar stenosis without spondylolisthesis got benefit from surgery. They showed reduction in pain reported in the lower limbs (VAS Leg with p < 0.05) and improved function (Oswestry with p < 0.05) whoever there was no significance change regarding visual analogue scale (VAS) between the two groups. In addition, there was no significant difference between the result between 6 month and oneyear follow up. Conclusion: In patients with lumbar stenosis in old age, there was improvement in leg pain and function in patients underwent surgical posterior decompression but there was no difference in back pain compared to patients underwent conservative management.

Effectiveness of Virtual Reality and Visual Feedback on Balance and Leg Function in Children with Cerebral Palsy

Research background. Virtual reality and visual feedback improve motor performance, motor function and balance, so we want to fnd if it affects the function of legs and balance of children with spastic hemiplegia. Research aim was to establish if the use of virtual reality and visual feedback with traditional physiotherapy improve the function of legs and balance of children with cerebral palsy. Methods. Nine children with cerebral palsy participated in the research. Participants were randomly divided into two groups – virtual reality group (n = 6) and control (n = 3). Virtual reality group practised exergaming and stretching exercises for 10 weeks, twice a week. Control group practiced conventional physiotherapy and stretching exercises for 6 weeks, twice a week. We measured the range of motion of the lower limb, spasticity of the lower limb using Modifed Ashworth’o Scale, static, dynamic balance, trunk coordination using Trunk Impairment Scale at the start and the end of the research, and balance using Pediatric Balance Scale. Results. Virtual reality and visual feedback reduced the spasticity of the lower limb, improved balance and postural control for children with cerebral palsy, but it did not improve the range of motion of the lower limb of children with cerebral palsy. Conclusions. Virtual reality and visual feedback did not improve the range of motion of the lower limb of children with cerebral palsy. Virtual reality and visual feedback reduced spasticity of the lower limb, improved balance and postural control for children with cerebral palsy.Keywords. Cerebral palsy, virtual reality, visual feedback, postural control, muscle architecture.