The Effect of Leg Dominance in Patients on Perforator-Based Flaps Elevated From the Lower Extremities.

BACKGROUND: The lower extremities are the largest donor sites in the body for perforator flap reconstruction. Multislice row computed tomography angiography allows for a multiplanar assessment of perforators using a large number of three-dimensional images with high resolution. In this study, the effect of leg dominance on perforator flap donor site preference was investigated radiologically to increase preoperative perforator mapping precision and surgical success. PATIENTS AND METHODS: The study included 40 patients. Superior gluteal artery perforator (SGAP) flap, inferior gluteal artery perforator (IGAP) flap, superficial circumflex iliac artery perforator flap, anterolateral thigh (ALT) flap, profunda artery perforator (PAP) flap, medial sural artery perforator (MSAP) flap, peroneal artery perforator (PP) flap, and posterior tibial artery perforator (PTAP) flap were analyzed according to their number of perforators (> 0.8-mm perforators counted, number of larger perforators [nLP]), dominant perforator diameter (DPD), related muscle thickness (RMT), and related subcutaneous tissue thickness (RSTT) in each leg. RESULTS: Of these 40 patients, 35 (87.5%) were right-leg dominant and 5 (12.5%) were left-leg dominant. The dominant leg had higher DPD for MSAP, PTAP, and PP than the nondominant leg (p = 0.08, p = 0.06, and p = 0.06, respectively). The dominant leg had a significantly higher nLP (> 0.8 mm) in MSAP, PTAP, and PP flaps than the nondominant leg (p < 0.05). Except for the PAP flap (adductor magnus muscle; p > 0.05), RMT of all other perforator flaps (SGAP, IGAP, ALT, MSAP, PTAP, and PP) was statistically higher in the dominant leg (p < 0.05). There was no statistically significant difference in RSTT between any of the two groups (p > 0.05). CONCLUSION: According to findings, the dominant leg could be considered a donor site preference to improve surgical outcomes and reduce microsurgical complications due to an increased nLP, perforator diameter, and RMT.

Effect of mediolateral leg perturbations on walking balance in people with chronic stroke: A randomized controlled trial.

Many people with chronic stroke (PwCS) exhibit deficits in step width modulation, an important strategy for walking balance. A single exposure to swing leg perturbations can temporarily strengthen this modulation. The objective of this parallel, double-blinded, randomized controlled trial was to investigate whether repeated perturbations cause sustained increases in step modulation (NCT02964039; funded by the VA). 54 PwCS at the Medical University of South Carolina were randomly assigned to one of three intervention groups: Control (n = 18), with minimal forces; Assistive (n = 18), pushing the swing leg toward a mechanically appropriate location; Perturbing (n = 18), pushing the swing leg away from a mechanically appropriate location. All intervention groups included 24 training sessions over 12-weeks with up to 30-minutes of treadmill walking while interfaced with a novel force-field and a 12-week follow-up period, with five interspersed assessment sessions. Our primary outcome measure was paretic step width modulation, the partial correlation between step width and pelvis displacement (ρSW). Secondarily, we quantified swing and stance leg contributions to step modulation, clinical assessments of walking balance and confidence, and real-world falls. Outcomes were analyzed for participants who completed all assessment sessions (n = 44). Only the Perturbing group exhibited significant increases in paretic ρSW, which were present after 4-weeks of training and sustained through follow-up (t = 2.42-3.17). These changes were due to improved control of paretic swing leg positioning. However, perturbation-induced changes in step modulation were not always significantly greater than those in the Control group, and clinical assessments were similar across intervention groups. Participants in the Perturbing group experienced a lower fall rate than those in the Control group (incidence rate ratio = 0.53), although our small sample size warrants caution. The present results indicate that perturbations can cause sustained modifications of targeted biomechanical characteristics of post-stroke gait, although such changes alone may be insufficient to change more complex clinical assessments.

Evaluation of Neuromuscular Blockade: A Comparative Study of TOF-Cuff® on the Lower Leg and TOF-Scan® on the Ulnar Nerve During Mivacurium Anesthesia.

BACKGROUND To evaluate neuromuscular monitoring during anesthesia with mivacurium, this study assessed the correlation between measurements of TOF-Cuff® placed on the lower leg and stimulating the tibial nerve and TOF-Scan® values from the adductor pollicis muscle. Additionally, systolic (SBP) and diastolic (DBO) blood pressure measured in both locations were compared. MATERIAL AND METHODS Twenty-six patients participated in this observational clinical trial. The TOF-Cuff® was placed on the lower leg and the TOF-Scan® was placed on the thumb. Train-of-four (TOF) values were recorded simultaneously by both devices at 30-second intervals before intubation. Measurements continued every 5 minutes until extubation. Bland-Altman analyses compared TOF values obtained from the 2 devices. RESULTS Time to onset and relaxation time did not differ significantly; the number of patients presenting a lack of blockade despite TOF=0 was also concordant. The time from the last dose of mivacurium to TOF ratio >90 was shorter on the leg than on hand (median 20 [5-28, 0-65] min vs 30 [20-35, 0-60] min, p=0.025). The median (range, interquartile range) difference between measurements was: 11.6 (-41 to 45, 2-19) for SBP and -8 (-28 to 26, -15 to -4) for DBP at baseline (p=0.0495); 5 (-53 to 55, -2 to 9) for SBP and -11 (-45 to 29, -19 to -5) (p=0.0017) for DBP during the blockade. CONCLUSIONS Time-to-onset and SBP are comparable between these 2 methods, in contrast to time-to-recovery and diastolic blood pressure, and this should be considered in case of the inability to apply the TOF-Cuff on the leg.

Comparison of the utility of SARC-F, SARC-CalF, and calf circumference as screening tools for sarcopenia in patients with osteoporosis.

AIM: Patients with osteoporosis who also have sarcopenia are at a high risk for falls and fractures. Early detection of sarcopenia is crucial for these patients. This study aimed to compare the effectiveness of SARC-F, SARC-CalF, and calf circumference (CC) as screening tools for sarcopenia in patients with osteoporosis. METHODS: This cross-sectional study was retrospectively conducted on patients who attended the outpatient clinic for Osteoporosis and Sarcopenia at Kyoto Medical Center. Sarcopenia was determined based on low skeletal muscle mass and weak handgrip strength. Sensitivity and specificity analyses were conducted on SARC-F, SARC-CalF, and CC. The diagnostic utility of these three tools was compared using the receiver-operating characteristic (ROC) curves and the area under the ROC curves (AUC). RESULTS: A total of 225 patients (men/women: 33/192) with a median age of 69.0 years (interquartile range: 61.0‒75.0) were enrolled. The prevalence of sarcopenia was found to be 11.6%. CC had the highest sensitivity (80.8%), while SARC-F had the highest specificity (93.0%) for detecting sarcopenia. ROC analysis revealed that all three tools had significant potential for sarcopenia diagnosis, with SARC-CalF having the highest AUC compared to SARC-F and CC (0.753 vs. 0.619 and 0.700). A multivariate logistic regression, incorporating other confounders as explanatory variables, revealed that SARC-CalF was independently related to sarcopenia (odds ratio: 14.80, 95% confidence interval: 3.83-57.30, p < 0.001). CONCLUSION: In patients with osteoporosis, SARC-CalF is more effective in the early detection of sarcopenia than SARC-F and CC.

Impact of contraction intensity and ankle joint angle on calf muscle fascicle length and pennation angle during isometric and dynamic contractions.

During muscle contraction, not only are the fascicles shortening but also the pennation angle changes, which leads to a faster contraction of the muscle than of its fascicles. This phenomenon is called muscle gearing, and it has a direct influence on the force output of the muscle. There are few studies showing pennation angle changes during isometric and concentric contractions for different contraction intensities and muscle lengths. Therefore, the aim was to determine these influences over a wide range of contraction intensities and ankle joint angles for human triceps surae. Additionally, the influence of contraction intensity and ankle joint angle on muscle gearing was evaluated. Ten sport students performed concentric and isometric contractions with intensities between 0 and 90% of the maximum voluntary contraction and ankle joint angles from 50° to 120°. During these contractions, the m. gastrocnemius medialis and lateralis and the m. soleus were recorded via ultrasound imaging. A nonlinear relationship between fascicle length and pennation angle was discovered, which can be described with a quadratic fit for each of the muscles during isometric contraction. A nearly identical relationship was detected during dynamic contraction. The muscle gearing increased almost linearly with contraction intensity and ankle joint angle.

Simple and Safe Soft-Tissue Coverage Technique Using the Bipedicled Flap in the Lower Leg.

Background: Skin and soft-tissue defects in the lower legs present significant challenges for surgeons, especially when tendons, bones, or implants are exposed. In such cases, simple dressings or skin grafts are insufficient, necessitating flap surgery. The bipedicled flap is a simpler and more reliable method with a high success rate compared to other flaps, showing minimal flap failures. This study aimed to examine the advantages and limitations of using a bipedicled flap for soft-tissue reconstruction in the lower legs. Methods: This retrospective study reviewed medical records from January 2013 to May 2020, involving 10 bipedicled flaps performed on the lower legs. The study included 5 male and 5 female patients, with an average age of 54.5 years. The defects were due to various causes, including trauma, tumor surgery, postoperative complications such as dehiscence and skin necrosis, and chronic osteomyelitis. The size of the defects ranged from 4 × 3 cm to 16 × 13 cm. The outcomes assessed included flap viability, postoperative complications, and patient satisfaction. Patient satisfaction was assessed on a 15-point scale, evaluating appearance, function, and sensation with up to 5 points each, and categorizing scores as poor (1-3), below average (4-6), average (7-9), good (10-12), and excellent (13-15). Results: All flaps were successfully performed, and there were no cases showing any special complications. Patient satisfaction following the operation was excellent in 3 patients, good in 6 patients, and average in 1 patient, with an overall average score of 11.5 (good) out of 15 among the 10 patients evaluated. Conclusions: The bipedicled flap is a simple and secure method for treating soft-tissue defects in the lower legs. Therefore, this technique can be considered as one of the viable options for treating such defects.

Fast Competitive Swimmers Demonstrate a Diminished Diving Reflex.

Competitive swimmers complete 50-m front crawl swimming without breathing or with a limited number of breaths. Breath holding during exercise can trigger diving reflex including bradycardia and diminished active muscle blood flow, whereas oxygen supply to vital organ such as brain is maintained. We hypothesized that swimmers achieving faster time in 50-m front crawl with limited number of breaths demonstrate a blunted diving reflex of cardiac and active muscle blood flow responses with elevated cerebral perfusion to counteract peripheral and central fatigues. Twenty-eight competitive swimmers (12 females) underwent a 50-m front crawl swimming time trial with minimum respiratory interruptions, following which they were categorized into two groups: Fast (n = 13) and Slow (n = 15). Additionally, they performed knee extension exercises with maximal voluntary breath- holding, wherein leg blood flow (Doppler ultrasound), cardiac output (Modelflow), heart rate (electrocardiogram), and middle cerebral artery mean blood velocity (transcranial Doppler ultrasound) were evaluated. The pattern of leg blood flow response differed between the two groups (p = 0.031) with the Fast group experiencing a delayed onset of reductions in leg blood flow (p = 0.035). The onset of bradycardia was also delayed in the Fast group (p = 0.014), with this group demonstrating a higher value of the lowest heart rate (between-trial difference in average: 15.9 [3.73, 28.2] beats/min) and cardiac output (between-trial difference in median: 2.84 L/min) (both, p ≤ 0.013). Middle cerebral artery mean blood velocity was similar between the groups (all p ≥ 0.112). We show that swimmers with superior performance in 50-m front crawl swim with limited breaths display a diminished diving reflex.

Positive effects of lower extremity constraint-induced movement therapy on balance, leg strength and dual-task ability in stroke patients: a longitudinal cohort study.

OBJECTIVE: To investigate whether high-intensity lower extremity constraint-induced movement therapy can improve balance, leg strength, and dual-task ability. DESIGN: A longitudinal cohort study in a real-world outpatient clinic. PATIENTS: 147 community-dwelling participants in the subacute and chronic poststroke phases. METHODS: Participants received lower extremity constraint-induced movement therapy for 6 hours/day during 2 consecutive weeks, including balance, strength, and functional training. The Berg Balance Scale (BBS), Single-Leg-Stance (SLS) bilaterally, one Repetition Maximum (1RM) in a leg press, symmetry of leg strength (Diff-1RM), Timed Up and Go (TUG), and the TUG Manual test were assessed before, after, and 3 months after lower extremity constraint-induced movement therapy. RESULTS: Compared with preintervention data, statistically significant improvements after lower extremity constraint-induced movement therapy (p < 0.001) were demonstrated for balance with an absolute value in BBS at 1.9 points (effect size 0.38) and SLS at 2.4 s (effect size 0.24), and for leg strength at 10.2 kg (effect size 0.54) for the affected leg. Diff 1RM decreased significantly at 5.8 kg (effect size 0.39) and improvements on dual-task ability at 2.7 s were significant (effect size 0.14). The effects persisted at the 3-month follow-up. CONCLUSIONS: High-intensity lower extremity constraint-induced movement therapy may be a feasible treatment option for middle-aged stroke patients to affect balance, leg strength, and dual-task ability positively in an out-patient clinical setting.

The Rate of Leg Fat Oxidation Is Not Attenuated During Incremental Intensity One-Leg Knee Extensor Exercise.

It is not clear if fat oxidation is attenuated at higher exercise intensities, when exercising with a small muscle mass, and therefore, we studied leg fat oxidation during graded one-leg exercise. Ten males (age: 27 ± 2 years, body mass: 82 ± 3 kg, BMI: 24 ± 1 kg m-2, V̇O2max: 49 ± 2 mL min-1 kg-1) performed one-leg exercise at 25% of maximal workload (Wmax) for 30 min, followed by 120-min exercise at 55% Wmax with the contralateral leg, and finally 30-min exercise at 85% Wmax with the first leg. Blood was sampled from an artery and both femoral veins, and blood flow was determined using Doppler ultrasound. Muscle biopsies were obtained before and after 30 min at each workload. One-way RM ANOVA was applied to determine the impact of exercise intensity. Data are expressed as mean ± SEM. From rest through exercise average blood flow (0.4 ± 0.1, 2.1 ± 0.1, 2.6 ± 0.2, 3.7 ± 0.2 L min-1) and oxygen uptake across the leg (0.03 ± 0.01, 0.23 ± 0.02, 0.35 ± 0.03, 0.53 ± 0.04 L min-1) increased with exercise intensity (p < 0.001). Leg RQ (0.76 ± 0.04, 0.86 ± 0.02,0.87 ± 0.01, 0.92 ± 0.01, p < 0.001), leg plasma FA uptake (2 ± 2, 46 ± 8,83 ± 9, 114 ± 16 µmol min-1; p < 0.001) and rate of leg fat oxidation (0.016 ± 0.005, 0.062 ± 0.012, 0.075 ± 0.011, 0.084 ± 0.018 g min-1, p < 0.007) increased with exercise intensity. Muscle-free carnitine content was unchanged from rest at 25% Wmax and decreased after 30 min exercise at 55% and 85% Wmax (17.4 ± 1.6, 16.6 ± 0.7, 14.5 ± 1.2, 10.5 ± 1.0 mmol/kg dry muscle, respectively; p < 0.006). During incremental one-leg exercise, the rate of leg fat oxidation was not attenuated with increasing exercise intensity, probably due to an insufficient muscle metabolic stress response.

Correlation of Calf Circumference with Body Weight of 5-10 Years Aged Bangladeshi Children.

The cross-sectional, analytic and descriptive type study was conducted among 5-10 years aged Bangladeshi children at different areas of Mymensingh district (Muktagacha, Fulbaria, Trishal, Haluaghat and Fulpur thana) on 109 Bangladeshi children (39 female and 70 male). The study was conducted in the Department of Anatomy, Mymensingh Medical College, Bangladesh. Nonrandom purposive sampling technique was taken for sample collection. Any kind of leg and foot deformity resulting either from congenital anomaly or physical injury was excluded to construct standard data. The present anthropometric study was designed to construct data of 5-10 years aged Bangladeshi children regarding calf circumference, to measure correlation calf circumference (right) with body weight and comparison of calf circumference (right) between male and female children. The study has been made out to grow interest among the researchers for future study and also to compare the data with the data of the people of other races of different country. Body weight was recorded by weighing machine and calf circumference was measured by measuring tape. Calf circumference (right) showed non-significant positive correlation with weight in 5 years old male, 6 and 7 years old male and female, 8 years old male, 9 years old female and 10 years old male and female children. In case of 5 years old female and 9 years old male children, it showed significant positive correlation with weight but in case of 8 years old female, it showed non-significant negative correlation with weight. Comparison of calf circumference (right) between male and female children was done by Unpaired Students' 't' test which was statistically non-significant.

A Cross-Sectional Study of the Normative Data of the Side-To-Side Soleus Hoffmann Reflex from the Calf Muscle in Healthy Individuals in the Lying Down Position.

The goal of this study was to find out from the calf muscle, the normal H-reflex is in a group of healthy adults. This study is conducted for the period of one year in 2020-2021, in the department of Physiology AIIMS Bhopal, 119 adult male healthy volunteers who were asymptomatic from peripheral neuropathy and had a mean age of 30.40±6.78 were evaluated, to compare the normative tibial H reflex to their stature, body mass index, core body temperature, and limb length. The parameters considered were M- Latency, H-Latency, M-Amplitude, H- Amplitude and H/M Ratio in their left and right legs, respectively. A total of 111 participants (93.3%) were in the age group of 40 years or younger, with the mean age (in years) being 30.40±6.78. Only eight (8) participants (6.7%) belonged to the over-40 age group. The average weight (Kg), height (cm), and limb length (cm) were 173.11 cm, 10.48 cm, and 94.28 cm respectively. The mean ±SD latencies of the H reflex were 30.93±4.42 and 31.01±5.21 milliseconds in the right and left legs, respectively. Leg length and H reflex latency had a significant correlation (r = 0.55, p=0.05). There was no discernible correlation between age and the H reflex latency. The right and left H reflex latencies should vary by no more than 1.8 ms to be deemed normal. This research examined tibia H-reflex side-to-side latency variability and amplitude. Neurologic function may be assessed using the H-reflex. Due of its sensitivity to external circumstances, the H-reflex must be elicited carefully. The H-reflex may reveal neuronal function following damage if assessed appropriately.

Distally based sural flaps for soft tissue defects following traumatic osteomyelitis of lower leg and foot.

This retrospective study aimed to determine the incidence and risk factors for osteomyelitis recurrence and present our experiences in treating traumatic osteomyelitis in the lower leg and foot. We retrospectively reviewed data from 174 patients with distally based sural flaps for treating traumatic osteomyelitis with soft tissue defects in the lower leg and foot from November 2003 to February 2021. Possible risk factors for osteomyelitis recurrence were compared between the osteomyelitis control and recurrence groups. A total of 162 (93.1%) flaps survived uneventfully, while 12 (6.9%) flaps developed partial necrosis. Five patients had a bone defect with an average length of 5 cm. The free vascularized bone grafts were performed in two patients, and bone transportations were performed in three patients. All patients were followed up with an average period of 72.8 months. There were 152 patients (87.4%) in control group and 22 patients (12.6%) in recurrence group. The recurrence rates of osteomyelitis were significantly higher when the patient's age was 40 years or more and the duration was 10 weeks or more (P < 0.05). Cierny-Mader (C-M) classification type IV osteomyelitis was also significantly associated with osteomyelitis recurrence (p = 0.049). This flap combined with appropriate osteomyelitis treatment was an effective method to treat traumatic osteomyelitis of lower leg and foot with a soft tissue defect. Both patient age ≥ 40 years old and C-M type IV osteomyelitis were nonnegligible risk factors for osteomyelitis recurrence.

Calf circumference was negatively associated with all-cause mortality among the Chinese centenarians: a prospective study with a 5-year follow-up.

BACKGROUND: Sarcopenia is an aging-related disorder characterized by a loss of muscle mass and function. Calf circumference (CC) is a useful surrogate marker of muscle mass and function. This prospective study was designed to investigate the association between CC and all-cause mortality during a follow-up for 5 years in the Chinese centenarians. METHODS: The China Hainan Centenarian Cohort Study (CHCCS) is conducted in 18 cities and counties of Hainan, China. RESULTS: All 231 centenarians had a mean age of 103.03 years. Survival participants had a longer CC and were often living alone compared with others (P<0.05 for all). Multivariate Cox regression models showed that CC was negatively associated with all-cause mortality (P < 0.05 for all). Participants with a longer CC had a lower mortality risk compared with others [Exp(ß): 0.918; 95%confidence interval: 0.863-0.977]. Participants with a longer CC had a lower mortality risk whether they were males or females and lived with family members or alone. CONCLUSION: CC was negatively associated with all-cause mortality and could be an indicator of future mortality among the Chinese centenarians. Further researches should focus on preventing a decline in the CC in order to promote human longevity.

Telemedicine in pediatric rheumatology: the video pediatric gait, arms, legs, and spine (v-pGALS) examination.

Background/aim: Video pediatric gait, arms, leg, and spine (v-pGALS) is a virtual application of the pediatric gait, arms, leg, and spine (pGALS) examination performed by video. We aimed to verify the applicability, validity, and accuracy of the Turkish translation of v-pGALS in a large pediatric patient cohort. Materials and methods: Children aged 4-18 years seen between May and June 2022 were included. A hands-on physical examination and v-pGALS were performed. Demographics, active symptoms, physical examination findings, diagnosis, and v-pGALS findings were recorded. The acceptability of v-pGALS, in terms of additional distress and duration, was measured by the parent/patient using a visual analog scale (VAS). Results: 102 patients (median age 12.41 years) were included. Juvenile idiopathic arthritis (JIA) was the most common diagnosis. The median duration of v-pGALS was 7 min. An abnormal v-pGALS was identified in 25 patients while the hands-on physical examination was abnormal in 27 patients. Scoliosis and pes planus were missed in v-pGALS. Both children and parents gave a median VAS score of 0 for additional discomfort and duration. That is, the duration of v-pGALS was acceptable for ≥98% of the patients/parents, and ≥98% mentioned that it caused little/no discomfort. The sensitivity and specificity of v-pGALS were 92.6% and 100%, respectively, for the detection of musculoskeletal (MSK) abnormalities. Conclusion: The v-pGALS is an applicable, accurate, and practical tool for evaluating MSK problems in children. The Turkish translation was also conveniently acceptable.

Using Wavelet Analysis of Blood Flow Oscillations to Investigate Differences in Skin Blood Flow Regulations Between the Upper and Lower Limbs.

BACKGROUND: The objective of this study was to investigate the differences in skin blood flow regulations between the upper and lower limbs in healthy adults using wavelet analysis of skin blood oscillations. To the best of our knowledge, this is the first study investigating the dominant skin blood flow control of the upper and lower limbs in healthy adults. METHODS: Skin blood flow of the forearm and leg was simultaneously measured by laser Doppler flowmetry (LDF) in 17 healthy adults. Skin blood flow oscillations were analyzed using wavelet analysis to assess the dominant control among the metabolic endothelial (0.0095-0.02 Hz), neurogenic (0.02-0.05 Hz), myogenic (0.05-0.15 Hz), respiratory (0.15-0.4 Hz), and cardiac (0.4-2 Hz) origins. RESULTS: Skin blood flow in the leg (11.13 ± 4.90 perfusion unit) was significantly higher than in the forearm (6.90 ± 2.50 perfusion unit, p < 0.001). The metabolic endothelial control is more dominant in the forearm (1.19 ±0.51 au) compared to the leg (0.73 ± 0.41 au, p < 0.01). The myogenic control is more dominant in the leg (1.18 ± 0.28 au) compared to the forearm (0.96±0.18 au, p < 0.05). CONCLUSION: Through wavelet analysis of skin blood flow oscillations, the results indicate that metabolic endothelial control is more dominant in the forearm (upper limbs) and myogenic control is more dominant in the leg (lower limbs).

Enhanced phasic calf muscle activation with swing resistance enhances propulsion of the paretic leg in people poststroke.

Reduced propulsion of the paretic leg contributes to impaired walking in people poststroke. The goal of this study was to determine whether phasic electrical stimulation to the paretic gastrocnemius muscle combined with resistance applied to the nonparetic leg during swing phase while walking would enhance muscle activation of the paretic gastrocnemius and propulsive force of the paretic leg. Fifteen individuals who had a stroke visited the lab once to complete two experimental sessions (i.e., crossover design; session order randomized). Each session consisted of 1) treadmill walking with either "motor stimulation and swing resistance" or "swing resistance only" (10-min walking: 1-min baseline, 7-min adaptation to intervention, and 2-min postadaptation) and 2) instrumented treadmill walking before and after treadmill walking. Participants showed enhanced muscle activation of the paretic gastrocnemius (P = 0.03) and improved anteroposterior ground reaction force of the paretic leg (P = 0.01) immediately after the treadmill walking with "motor stimulation and swing resistance," whereas no improvements after the walking with "swing resistance only." Those enhanced gastrocnemius muscle activation (P = 0.02) and improved ground reaction force (P = 0.03) were retained until the late postadaptation period and 10 min after treadmill walking, respectively. Walking with "motor stimulation and swing resistance" may enhance forced use of the paretic leg and improve propulsive force of the paretic leg. Applying phasic electrical stimulation to the paretic gastrocnemius muscle and swing resistance to the nonparetic leg during walking can be used as a novel intervention strategy to improve motor control of the paretic leg and walking in people poststroke.NEW & NOTEWORTHY Applying targeted motor stimulation to the paretic calf muscle and swing resistance to the nonparetic leg during walking induced significant enhancement in muscle activation of the paretic gastrocnemius and anterior-posterior ground reaction force of the paretic leg, whereas no enhancements were observed after walking with swing resistance only. Furthermore, the enhanced gastrocnemius muscle activation and ground reaction force of the paretic leg were partially retained at the late postadaptation period and 10 min after treadmill walking.

A New Measure for Quantifying Four-Limb Coordination of Human Gait Based on Mobility Sensors.

Coordinated movement of four limbs is a hallmark of healthy locomotion. No measures exist to quantify four-limb coordination. This study aimed to investigate temporal four-limb coordination and proposed a new metric for quantifying the inter-limb phase of rhythmic locomotion-related movements. Kinetic data of arm and leg movements generated during walking (self-selected speed) from healthy adults were used to extract the phases (φ) between all possible limb pairings. The φ series were used to calculate each pair's Phase Coordination Index (PCI). The PCI quantifies the accuracy and consistency of generating anti-phased rhythmic movements (lower PCI values mean better coordination). We also calculated the Quadruple-PCI (Q-PCI) by combining all φ values of all limb pairs. We found a significant correlation between the PCI values of all limb pairings and the Q-PCI (pairs involving arms: Pearson's R > 0.79, p < 0.001; leg-leg: Pearson's R = 0.3, p < 0.01). The PCI values that involve arms (median values between 6.5% and 8.3%) were significantly higher than the leg-leg PCI (median values between 3.8% and 4.1%), and the Q-PCI (median values between 8.3% and 9.7%) was significantly higher than all other PCI values. We also found a negative correlation between the arm swing amplitude and the PCI values (Spearman's Rho of different limb pairings ranging from -0.25 to -0.5, p < 0.05), suggesting that higher arm swing amplitude leads to better coordination. Four-limb coordination analysis is a novel method for comprehensive assessment of gait coordination, which is often compromised among persons with disabilities.

Trunk-to-leg volume and appendicular lean mass from a commercial 3-dimensional optical body scanner for disease risk identification.

BACKGROUND & AIMS: Body shape expressed as the trunk-to-leg volume ratio is associated with diabetes and mortality due to the associations between higher adiposity and lower lean mass with Metabolic Syndrome (MetS) risk. Reduced appendicular muscle mass is associated with malnutrition risk and age-related frailty, and is a risk factor for poor treatment outcomes related to MetS and other clinical conditions (e.g.; cancer). These measures are traditionally assessed by dual-energy X-ray absorptiometry (DXA), which can be difficult to access in clinical settings. The Shape Up! Adults trial (SUA) demonstrated the accuracy and precision of 3-dimensional optical imaging (3DO) for body composition as compared to DXA and other criterion measures. Here we assessed whether trunk-to-leg volume estimates derived from 3DO are associated with MetS risk in a similar way as when measured by DXA. We further explored if estimations of appendicular lean mass (ALM) could be made using 3DO to further improve the accessibility of measuring this important frailty and disease risk factor. METHODS: SUA recruited participants across sex, age (18-40, 40-60, >60 years), BMI (under, normal, overweight, obese), and race/ethnicity (non-Hispanic [NH] Black, NH White, Hispanic, Asian, Native Hawaiian/Pacific Islander) categories. Each participant had whole-body DXA and 3DO scans, and measures of cardiovascular health. The 3DO measures of trunk and leg volumes were calibrated to DXA to express equivalent trunk-to-leg volume ratios. We expressed each blood measure and overall MetS risk in quartile gradations of trunk-to-leg volume previously defined by National Health and Nutrition Examination Survey (NHANES). Finally, we utilized 3DO measures to estimate DXA ALM using ten-fold cross-validation of the entire dataset. RESULTS: Participants were 502 (273 female) adults, mean age = 46.0 ± 16.5y, BMI = 27.6 ± 7.1 kg/m2 and a mean DXA trunk-to-leg volume ratio of 1.47 ± 0.22 (females: 1.43 ± 0.23; males: 1.52 ± 0.20). After adjustments for age and sex, each standard deviation increase in trunk-to-leg volume by 3DO was associated with a 3.3 (95% odds ratio [OR] = 2.4-4.2) times greater risk of MetS, with individuals in the highest quartile of trunk-to-leg at 27.4 (95% CI: 9.0-53.1) times greater risk of MetS compared to the lowest quartile. Risks of elevated blood biomarkers as related to high 3DO trunk-to-leg volume ratios were similar to previously published comparisons using DXA trunk-to-leg volume ratios. Estimated ALM by 3DO was correlated to DXA (r2 = 0.96, root mean square error = 1.5 kg) using ten-fold cross-validation. CONCLUSION: Using thresholds of trunk-to-leg associated with MetS developed on a sample of US-representative adults, trunk-to-leg ratio by 3DO after adjustments for offsets showed significant associations to blood parameters and MetS risk. 3DO scans provide a precise and accurate estimation of ALM across the range of body sizes included in the study sample. The development of these additional measures improves the clinical utility of 3DO for the assessment of MetS risk as well as the identification of low muscle mass associated with poor cardiometabolic and functional health.