Effects of Bilateral or Unilateral Plyometric Training of Lower Limbs on the Bilateral Deficit During Explosive Efforts.

OBJECTIVES: Bilateral Deficit (BLD) occurs when the force generated by both limbs together is smaller than the sum of the forces developed separately by the two limbs. BLD may be modulated by physical training. Here, were investigated the effects of unilateral or bilateral plyometric training on BLD and neuromuscular activation during lower limb explosive extensions. METHODS: Fourteen young males were randomized into the unilateral (UL_) or bilateral (BL_) training group. Plyometric training (20 sessions, 2 days/week) was performed on a sled ergometer, and consisted of UL or BL consecutive, plyometric lower limb extensions (3-to-5 sets; 8-to-10 repetitions). Before and after training, maximal explosive efforts with both lower limbs or with each limb separately were assessed. Electromyography of representative lower limb muscles was measured. RESULTS: BL_training significantly and largely decreased BLD (p=0.003, effect size=1.63). This was accompanied by the reversion from deficit to facilitation of the electromyography amplitude of knee extensors during bilateral efforts (p=0.007). Conversely, UL_training had negligible effects on BLD (p=0.781). Also, both groups showed similar improvements in their maximal explosive power generated after training. CONCLUSIONS: Bilateral plyometric training can mitigate BLD, and should be considered for training protocols focused on improving bilateral lower limb motor performance.

Dynamic comparison the lower extremities length in students education in higher institutions.

OBJECTIVE: Aim: Dynamic comparison of the lower limbs length, depending on the type of sport, followed by the construction of a mathematical model for predicting sports abilities. PATIENTS AND METHODS: Materials and Methods: The comparison of the lower limbs length in dynamics was carried out on 132 students of higher education institutions of Bukovyna. While the primary study was carried out during September-October 2021, next study of these same students was conducted in September-October 2022. The main group consists of 92 (69.7%) students, the control group - 40 (30.30%) students aged 16 to 18 years. All students underwent an anthropometric study (determination of the length of the lower limbs) according to the method of P.P. Shaparenka. The comparesment of anthropometric parameters in the main group depending on the type of sport used the Kruskel-Wallis test (non-parametric analysis of variance) in order to identify a reliable difference in the average indicators of the respondents depending on the type of sport (the median of the distribution was considered as a measure of central tendency). In order to establish which pairs of age groups had a statistical difference in the medians, the Conover-Iman test was used. A paired t-test (t-test of paired samples) was performed to compare the length of the respondents' lower limbs during the first measurement and again one year later. Statistical analysis of the obtained data was performed using the licensed RStudio program. RESULTS: Results: The distribution of the length of the right lower limb of the respondents of the main group by measurement shows that the average value of the length of the right lower limb has changed: a significant difference in the length of the right lower limb was found between the first (M = 88.812, SD = 5.287) and the second (M = 89.377, SD = 5.347) measurements; t (68) = -5.223, p < 0.001. The distribution of the length of the left lower limb shows that the average value of the length of the left lower limb has changed also: a significant difference in the length of the left lower limb was found between the first (M = 88.667, SD = 5.266) and the second (M = 89.435, SD = 5.309) measurements; t (68) = -8.289, p < 0.001. CONCLUSION: Conclusions: In order to dynamically compare the length of the lower limbs for comprehensive control and selection of promising students in football, volleyball, handball and basketball, a mathematical model was derived for predicting the length of the lower limbs, in corresponding sports: right lower limb y = 0.506 x and left y = 0.507x, where y - is the length of the left lower limb, x - is the height. The coefficient of determination is 99.8%. A significant predictor for the length of both lower limbs is the height.

Randomized comparative study of negative pressure wound therapy versus compression dressing on split-thickness skin grafts of the lower limbs in an elderly population.

INTRODUCTION: Failure to adequately secure the skin graft to the lower limbs recipient bed can result in loss of the graft. Our objective was to compare the healing of split-thickness skin grafts three weeks postoperatively, using either negative pressure wound therapy (NPWT) or conventional compression bandaging. METHODS: In this multicenter randomized controlled study, patients with tissue loss ranging from 50 cm2 to 600 cm2 on the lower limbs and treated with split-thickness skin grafts were included in three French hospitals. A digital photographic evaluation was performed at 3 weeks. RESULTS: During 9 years, 70 patients were included in the study and allocated to a treatment group. The grafted area was similar in both groups. Loss of graft was significantly reduced in the NPWT group with 14.6 cm2 compared to 29 cm2 in the control group (p = 0.0003). The hospital stay was also significantly reduced in the NPWT group, at 4 days versus 6.5 days in the control group (p = 0.0284). In the NPWT group, 60% reported pain compared to 22.9% in the control group (p = 0.0048). CONCLUSIONS: The use of NPWT dressings improves skin graft take by reducing necrosis, improving the graft's adherence to the recipient site, and reducing hospital length-of-stay.

Endovascular Management of Acute Lower Limb Ischemia Linked to Cocaine Abuse: A Case Report.

Cocaine abuse is a public health concern with well-documented cardiovascular complications. However, acute limb ischemia remains a rare and underreported consequence. We present a case of a 36-year-old man with acute right lower limb ischemia following heavy cocaine use, successfully managed with systemic heparin and intra-arterial nitroglycerin. The case highlights considering cocaine as a potential cause of acute limb ischemia and the efficacy of endovascular therapy. Further case reports with this diagnosis and their management are crucial for establishing the best strategies and improving outcomes in these scenarios.

Accuracy of EMG linear envelope in identifying the peak of muscular activity during walking.

BACKGROUND: The linear-envelope peak (LEP) of surface EMG signal is widely used in gait analysis to characterize muscular activity, especially in clinics. RESEARCH QUESTION: This study is designed to evaluate LEP accuracy in identifying muscular activation and assessing activation timing during walking. METHODS: Surface EMG signals from gastrocnemius lateralis (GL) and tibialis anterior (TA) were analyzed in 100 strides per subject (31 healthy subjects) during ground walking. Signals were full-wave rectified and low-pass filtered (cut-off frequency=5 Hz) to extract the linear envelope. LEP accuracy in identifying muscle activations and the associated error in peak detection were assessed by direct comparison with a reference method based on wavelet transform. LEP accuracy in identifying the timing of higher signalenergy levels was also assessed, increasing the reference-algorithm selectivity. RESULTS: The detection error (percentage number of times when LEP falls outside the correspondent reference activation interval) is close to zero. Detection error increases up to 70% for intervals including only signal energy higher than 90% of energy peak. Mean absolute error (MAE, the absolute value of the distance between LEP timing and the correspondent actual timing of the sEMG-signal peak computed by reference algorithm) is 54.1±20.0 ms. Detection error and MAE are significantly higher (p<0.05) in TA data compared to GL signals. Differences among MAE values detected adopting different values for LE cut-off frequency are not statistically significant. SIGNIFICANCE: LEP was found to be accurate in identifying the number of muscle activations during walking. However, the use of LEP to assess the timing of highest sEMG-signal energy (signal peak) should be considered carefully. Indeed, it could introduce a relevant inaccuracy in muscle-activation identification and peak-timing quantification. The type of muscle to analyze could also influence LEP performances, while the cut-off frequency chosen for envelope extraction appears to have a limited impact.

Effectiveness of Extracorporeal Shock Wave Therapy in Treatment of Spasticity of Different Aetiologies: A Systematic Review and Meta-Analysis.

Background: Spasticity is a motor disorder characterised by exaggerated movements of the tendons and accompanied by hyperreflexia and hypertonia. Extracorporeal shock wave therapy (ESWT) is used as a treatment for spasticity, although more evidence is needed on the effectiveness of this therapy in the treatment of spasticity. Therefore, the aim of this study was to assess the effectiveness ESWT in the treatment of upper and lower limbs spasticity in both children and adults through different aetiologies. Methods: A systematic search was performed in different databases from inception to December 2023. Random-effects meta-analysis was used to estimate the efficacy of ESWT on spasticity using the Modified Ashworth Scale. Results: Sixteen studies were included in the systematic review and meta-analysis. The effect of ESWT on spasticity measured with the Modified Ashworth Scale shows a significant decrease in spasticity in the upper limbs and in the lower limbs in adults with chronic stroke and in children with cerebral palsy, is more effective immediately after application, and maintains its effect up to 12 weeks post treatment. Conclusions: These findings are important for clinical practice since they show evidence that ESWT is effective in reducing spasticity in both children and adults.

Repetitive temporal interference stimulation improves jump performance but not the postural stability in young healthy males: a randomized controlled trial.

BACKGROUND: Temporal interference (TI) stimulation, an innovative non-invasive brain stimulation technique, has the potential to activate neurons in deep brain regions. The objective of this study was to evaluate the effects of repetitive TI stimulation targeting the lower limb motor control area (i.e., the M1 leg area) on lower limb motor function in healthy individuals, which could provide evidence for further translational application of non-invasive deep brain stimulation. METHODS: In this randomized, double-blinded, parallel-controlled trial, 46 healthy male adults were randomly divided into the TI or sham group. The TI group received 2 mA (peak-to-peak) TI stimulation targeting the M1 leg area with a 20 Hz frequency difference (2 kHz and 2.02 kHz). Stimulation parameters of the sham group were consistent with those of the TI group but the current input lasted only 1 min (30 s ramp-up and ramp-down). Both groups received stimulation twice daily for five consecutive days. The vertical jump test (countermovement jump [CMJ], squat jump [SJ], and continuous jump [CJ]) and Y-balance test were performed before and after the total intervention session. Two-way repeated measures ANOVA (group × time) was performed to evaluate the effects of TI stimulation on lower limb motor function. RESULTS: Forty participants completed all scheduled study visits. Two-way repeated measures ANOVA showed significant group × time interaction effects for CMJ height (F = 8.858, p = 0.005) and SJ height (F = 6.523, p = 0.015). The interaction effect of the average CJ height of the first 15 s was marginally significant (F = 3.550, p = 0.067). However, there was no significant interaction effect on the Y balance (p > 0.05). Further within-group comparisons showed a significant post-intervention increase in the height of the CMJ (p = 0.004), SJ (p = 0.010) and the average CJ height of the first 15 s (p = 0.004) in the TI group. CONCLUSION: Repetitive TI stimulation targeting the lower limb motor control area effectively increased vertical jump height in healthy adult males but had no significant effect on dynamic postural stability.

A retrospective clinicopathological study of erythema nodosum.

Erythema nodosum (EN) may be idiopathic or secondary, and usually resolves naturally within 1-2 months. In atypical EN cases, the rash extends beyond the lower limbs to the upper limbs and trunk, and histopathological findings may be accompanied by vasculitis in addition to septal panniculitis. Few studies have examined the differences in the clinical characteristics of patients with EN based on rash distribution. We retrospectively examined whether there was a correlation with clinical information, such as the presence or absence of underlying diseases, by classifying the patients into two groups: the lower limbs group (the EN rash was confined to the lower limbs) and the beyond lower limbs group (the EN rash appeared beyond the lower limbs). Among the 86 adult patients diagnosed with EN at the Dermatology Department of Fujita Medical University between 2015 and 2020, there were 65 cases of the lower limbs group and 21 cases of the beyond lower limbs group. The frequency of underlying diseases was significantly higher in the beyond lower limbs group (76.2%, 16 cases) than in the lower limbs group (40.0%, 26 cases; P < 0.005). Vasculitis was more notable in the beyond lower limbs group (P < 0.05). Significantly higher vasculitis was noted in the EN group with underlying diseases (30.2%, 13 cases) than in the idiopathic EN group without underlying diseases (11.6%, 5 cases; P < 0.05). Neutrophil extracellular traps were positive in approximately 40% of cases in both groups. In the beyond lower limbs group, the possibility of severe cases with underlying diseases, vasculitis, and inflammation must be considered for effective treatment.

Novel Angiogenesis Role of GLP-1(32-36) to Rescue Diabetic Ischemic Lower Limbs via GLP-1R-Dependent Glycolysis in Mice.

BACKGROUND: Restoring the capacity of endothelial progenitor cells (EPCs) to promote angiogenesis is the major therapeutic strategy of diabetic peripheral artery disease. The aim of this study was to investigate the effects of GLP-1 (glucagon-like peptide 1; 32-36)-an end product of GLP-1-on angiogenesis of EPCs and T1DM (type 1 diabetes) mice, as well as its interaction with the classical GLP-1R (GLP-1 receptor) pathway and its effect on mitochondrial metabolism. METHODS: In in vivo experiments, we conducted streptozocin-induced type 1 diabetic mice as a murine model of unilateral hind limb ischemia to examine the therapeutic potential of GLP-1(32-36) on angiogenesis. We also generated Glp1r-/- mice to detect whether GLP-1R is required for angiogenic function of GLP-1(32-36). In in vitro experiments, EPCs isolated from the mouse bone marrow and human umbilical cord blood samples were used to detect GLP-1(32-36)-mediated angiogenic capability under high glucose treatment. RESULTS: We demonstrated that GLP-1(32-36) did not affect insulin secretion but could significantly rescue angiogenic function and blood perfusion in ischemic limb of streptozocin-induced T1DM mice, a function similar to its parental GLP-1. We also found that GLP-1(32-36) promotes angiogenesis in EPCs exposed to high glucose. Specifically, GLP-1(32-36) has a causal role in improving fragile mitochondrial function and metabolism via the GLP-1R-mediated pathway. We further demonstrated that GLP-1(32-36) rescued diabetic ischemic lower limbs by activating the GLP-1R-dependent eNOS (endothelial NO synthase)/cGMP/PKG (protein kinase G) pathway. CONCLUSIONS: Our study provides a novel mechanism with which GLP-1(32-36) acts in modulating metabolic reprogramming toward glycolytic flux in partnership with GLP-1R for improved angiogenesis in high glucose-exposed EPCs and T1DM murine models. We propose that GLP-1(32-36) could be used as a monotherapy or add-on therapy with existing treatments for peripheral artery disease. REGISTRATION: URL: www.ebi.ac.uk/metabolights/; Unique identifier: MTBLS9543.

Cortical and spinal responses to short-term strength training and detraining in young and older adults in rectus femoris muscle.

INTRODUCTION: Strength training mitigates the age-related decline in strength and muscle activation but limited evidence exists on specific motor pathway adaptations. METHODS: Eleven young (22-34 years) and ten older (66-80 years) adults underwent five testing sessions where lumbar-evoked potentials (LEPs) and motor-evoked potentials (MEPs) were measured during 20 and 60% of maximum voluntary contraction (MVC). Ten stimulations, randomly delivered, targeted 25% of maximum compound action potential for LEPs and 120, 140, and 160% of active motor threshold (aMT) for MEPs. The 7-week whole-body resistance training intervention included five exercises, e.g., knee extension (5 sets) and leg press (3 sets), performed twice weekly and was followed by 4 weeks of detraining. RESULTS: Young had higher MVC (~ 63 N·m, p = 0.006), 1-RM (~ 50 kg, p = 0.002), and lower aMT (~ 9%, p = 0.030) than older adults at baseline. Young increased 1-RM (+ 18 kg, p < 0.001), skeletal muscle mass (SMM) (+ 0.9 kg, p = 0.009), and LEP amplitude (+ 0.174, p < 0.001) during 20% MVC. Older adults increased MVC (+ 13 N·m, p = 0.014), however, they experienced decreased LEP amplitude (- 0.241, p < 0.001) during 20% MVC and MEP amplitude reductions at 120% (- 0.157, p = 0.034), 140% (- 0.196, p = 0.026), and 160% (- 0.210, p = 0.006) aMT during 60% MVC trials. After detraining, young and older adults decreased 1-RM, while young adults decreased SMM. CONCLUSION: Higher aMT and MEP amplitude in older adults were concomitant with lower baseline strength. Training increased strength in both groups, but divergent modifications in cortico-spinal activity occurred. Results suggest that the primary locus of adaptation occurs at the spinal level.

Correlation between the vascular resistance index and arteriography for assessment of the distal arterial bed in chronic limb threatening ischemia.

Background: Patients with chronic limb threatening ischemia (CLTI) of the lower limbs (LL) undergo arteriography for revascularization surgery planning. Doppler ultrasound (DU) is non-invasive and can provide information about the distal arteries through measurement of the resistance index (RI). Objectives: To correlate the Rutherford Angiographic Classification with the RI for assessment of the distal arterial bed of the LL. Methods: A cross-sectional study, conducted at a public tertiary hospital with 120 patients with LL CLTI, from September 2019 to April 2022. The RI of arteries that were candidates for revascularization was compared with the images of the same arteries obtained using arteriography, using the Rutherford Angiographic Classification of the distal bed. Results: A total of 120 LL were assessed in 120 patients with a mean age of 68.6 years. The sample was 50.0% male and 90.0% of the patients in the sample were classified as Rutherford category five. The RI values found for the arteries of the leg exhibited a statistically significant positive correlation with the Rutherford Classification (anterior tibial, p< 0.01; posterior tibial, p = 0.012 fibular, p = 0.034; and dorsalis pedis, p < 0.001). Conclusions: In this study, RIs for the arteries of the leg measured using Doppler ultrasound exhibited a positive correlation with the Rutherford Classification. This index could be useful for assessment of the distal arterial bed of the lower limbs of patients with chronic limb threatening ischemia.

Assessing domain match and feasibility of candidate instruments matching with OMERACT endorsed domains to measure flare in knee and hip osteoarthritis.

PURPOSE: To evaluate the domain match (truth) and feasibility of candidate instruments assessing flare in knee and hip osteoarthritis (OA) according to the identified domains. MATERIAL AND METHODS: From a literature review (575 papers), instruments were selected and evaluated using the truth and feasibility elements of the OMERACT Filter 2.2. These were evaluated by 26 experts, including patients, in two Delphi survey rounds. The final selection was obtained by a vote. RESULTS: 44 instruments were identified. In Delphi Round 1, five instruments were selected. In Round 2, all instruments obtained at least 75 % in terms of content match with the endorsed domains and feasibility. In the final selection, the Flare-OA questionnaire obtained 100 % favorable votes. CONCLUSION: Through consensus of the working group, the Flare-OA questionnaire was selected as the best candidate instrument to move into a full assessment of its measurement properties using the OMERACT Filter 2.2.

Shoe choice may affect fencing lunge attack performance.

The purpose of this study was to investigate the differences in attack time and lower limb biomechanics when performing fencing lunge with fencing shoes (FS) and commonly used court shoes (CS). Additionally, the study aimed to evaluate whether fencing shoes with a heel cup (FSH) could reduce lower limb impact. Thirteen female collegiate fencers who had participated in national-level competitions were recruited for this study. Participants performed the lunge on a human-shaped target while wearing FS, FSH, or CS in a randomized order. Biomechanical data were collected using a 3D motion analysis system synchronized with a force plate. A signal light, and an accelerometer were attached to the target's head to initiate lunge movement and detect hit moment for calculating attack time. Attack time was significantly shorter when wearing FS (0.92 ± 0.05 s) and FSH (0.93 ± 0.07 s) compared to CS (0.96 ± 0.06 s). The maximum angular velocity of ankle plantarflexion in rear foot push-off phase was significantly slower when wearing FS and FSH than when wearing CS. The maximum knee posterior shear force, maximum knee flexion moment, and maximum ankle medial shear force during the front foot step phase were significantly greater when wearing FS than when wearing CS. These forces were significantly reduced or nearly significantly reduced when wearing FSH, and there were no significant differences compared to wearing CS. The maximum ankle medial shear force during the push-off phase in rear foot was the greatest when wearing FS but decreased significantly when using FSH. However, this force was still greater than when wearing CS. Wearing FS resulted in a higher loading rate (LR) on the front foot. This LR was reduced when a heel cup was used but still remained higher than when wearing CS. There were no significant differences in the forward extension of body, maximum ground reaction force, or center of pressure displacement during front foot step and rear foot push-off phases among the three shoe conditions. Wearing FS can enhance lunge performance, and the use of a heel cup can effectively reduce lower limb impact.

Translation, Cross-Cultural Adaptation and Validation of the Lymphedema Quality of Life Questionnaire (LYMQOL) in German-Speaking Patients with Lymphedema of the Lower Limbs.

The LYMQOL Leg questionnaire is the most widely used, evidence-based tool for the assessment of health-related quality of life (HRQoL) in patients with lower limb lymphedema (LLL). It has been translated into several languages, but a German version is currently lacking. The aim of our study was to validate a German translation of LYMQOL Leg. Translation and cross-cultural adaptation were performed in accordance with ISPOR principles. A total of 103 patients with LLL from Germany, Austria, and Switzerland were interviewed twice. The content and face validity assessments indicated that the German LYMQOL Leg questionnaire was acceptable for interviewing patients with lymphedema. Comparing the LYMQOL Leg with the SF-36 demonstrated good construct validity. Reliability determined by the test-retest procedure was good (intra-class-correlation coefficients 0.68-0.92). Cronbach's alpha values ranged from 0.76 to 0.90 in both interviews, showing an acceptable internal consistency. The four domains of the questionnaire reached a cumulative variance of 52.7% in the factor analysis. The association between the lymphedema stages and the LYMQOL Leg domain scores was not significant. In conclusion, the validity of the German version of LYMQOL Leg, called LYMQOL Bein, was confirmed and thus represents a suitable tool for measuring HRQoL in German-speaking patients with LLL.

The Coronal Alignment of Lower Limbs in the Adolescent Football and Ice Hockey Players.

Background: To investigate the influence of sport-specific activities on coronal axial alignment of the lower limbs in adolescent football and ice hockey players. Methods: This cross-sectional study targeted healthy adolescent male football and ice hockey players with at least 3 years of sports participation. 90 football and 38 ice hockey players aged 12-16 years were divided into five age-matched subgroups. Coronal alignment of the lower limbs was determined by measuring the players' intercondylar or intermalleolar (ICD-IMD) distance with a custom-made calliper. In addition, their sports history was recorded. An age-matched comparison between the two sports groups was performed using the two-way model ANOVA and a multiple regression model for ICD-IMD was constructed. Results were additionally compared with age-matched data from the general population published in recent literature. Results: A statistically significant increase in ICD-IMD values (p < 0.05) was found between 12 (football 0 mm; ice hockey - 64 mm) and 16 years (football 340 mm; ice hockey 310 mm) in both sports groups. Results of regression analysis of pooled group data showed that ICD-IMD has low positive correlation (r = 0.407; r2 = 0.168; p < 0.05) with time of participation in sport, but no association with age of athletes at the start of their sport participation (r = - 0.018; r2 = 0.000; p > 0.05). There were no statistically significant differences between the two groups at any time point. Both sports groups showed a significant increase in ICD-IMD values (mean 198 mm) after the age of 14 compared to the general population. Conclusions: Participation in football and ice hockey is associated with a similar increase in ICD-IMD in the adolescent years in male athletes. The observed increase was higher in both groups of athletes than in their peers who do not regularly participate in sports. Level of Evidence: Level 4 (case series).

Effects of diverse resistance training modalities on performance measures in athletes: a network meta-analysis.

Background: Jumping ability is one of the necessary qualities for athletes. Previous studies have shown that plyometric training and complex training including plyometrics can improve athletes' jumping ability. With the emergence of various types of complex training, there is uncertainty about which training method has the best effect. This study conducted a meta-analysis of randomized controlled trials of plyometric-related training on athletes' jumping ability, to provide some reference for coaches to design training plans. Methods: We systematically searched 3 databases (PubMed, Web of Science, and Scopus) up to July 2023 to identify randomized controlled trials investigating plyometrics related training in athletes. The two researchers conducted literature screening, extraction and quality assessment independently. We performed a network meta-analysis using Stata 16. Results: We analyzed 83 studies and found that complex training, which includes high-intensity intervals and plyometric exercises, was the most effective method for improving squat jumps (SURCA = 96%). In the case of countermovement jumps a combination of electrostimulation and plyometric training yielded the best results (SURCA = 97.6%). Weightlifting training proved to be the most effective for the standing long jump (SURCA = 81.4%), while strength training was found to be the most effective for the five bounces test (SURCA = 87.3%). Conclusion: Our current study shows that complex training performs more efficient overall in plyometric-related training. However, there are different individual differences in the effects of different training on different indicators (e.g., CMJ, SJ, SLJ, 5BT) of athletes. Therefore, in order to ensure that the most appropriate training is selected, it is crucial to accurately assess the physical condition of each athlete before implementation. Clinical Trial Registration: https://www.crd.york.ac.uk/PROSPERO/, Registration and protocol CRD42023456402.

Variable Pivot Gait Based a Novel Dynamics Correction Method for Human Lower Limbs Model.

The rationality of gait analysis directly affects the dynamics of human lower limbs in the sagittal plane, and recent studies on gait stage redivision lack the stage when both feet are not in complete contact with the ground. This paper proposes a novel variable pivot gait, which includes the stage when the heel of one foot and the toe of the other are in contact with the ground and a dynamics correction method based on this gait. First, the relative motion data between the foot and the ground are measured by motion capture experiments, and then a variable pivot gait is proposed in terms of the pivot transformation between the foot and the ground. Second, the dynamics modeling is conducted based on the principle of mechanisms of human lower limbs in each stage of the variable pivot gait. Third, a dynamics correction method is proposed to correct the foot dynamics when the foot is not in complete contact with the ground. The experiment and simulation show that the variable pivot gait is consistent with the actual motion of the foot relative to the ground. The effectiveness of the dynamics correction method is proved by comparing dynamics results (hip, knee, and ankle moments) with previous studies. The variable pivot gait and the dynamics correction method can be applied to the human lower limbs and lower-limb robots, providing a new avenue.

Research on dynamic comfort maintenance by measuring lower limb edema and seat pressure during simulated seated sleep in flight.

Objectives. Seated sleep during flight can bring significant discomfort to passengers. The objective of this research was to study passengers' dynamic comfort maintenance strategies in lower limb postural shifting during seated sleep in flight. Methods. Studies on seated sleep postures and sitting comfort were conducted. First, 40 participants were recruited to the observational research for collecting typical leg postures during seated sleep. Then, an experiment was conducted with the participants simulating seated sleep in the aircraft seat. The changes in lower limb edema and seat pressure in different postures were measured with a bioelectrical impedance device, near-infrared spectroscopy device and pressure mapping device. Results. Six postures were selected through the observational research. The experiment showed that tissues of the thighs and buttocks suffer alternate higher compression by shifting between the six postures. Lower limb edema is higher when the shanks are forward, while the tissue under the ischial tuberosity suffers higher compression when the shanks are neutral. Conclusion. Six motivations for passengers to shift each sitting posture to achieve dynamic comfort were summarized, which helps obtain alternating rest in different body parts. The suggestion of a leg position adjustment system was also proposed.

Interlimb Coordination during Double Support Phase of Gait in People with and without Stroke.

This study aims to identify differences between participants with and without stroke regarding the ipsilesional and contralesional lower limbs kinematics, kinetics, muscle activity and their variability during double support phase of gait. Eleven post-stroke and thirteen healthy participants performed 10 gait trials at a self-selected speed while being monitored by an optoelectronic motion capture system, two force plates and an electromyographic system. The following outcomes were evaluated during the double support: the time and the joint position; the external mechanical work on the centre of mass; and the relative electromyographic activity. Both, contralesional/ipsilesional and dominant/non-dominant of participants with and without stroke, respectively, were evaluated during double support phase of gait in trailing or leading positions. The average value of each parameter and the coefficient of variation of the 10 trials were analysed. Post-stroke participants present bilateral decreased mechanical work on the centre of mass and increased variability, decreased contralesional knee and ankle flexion in trailing position, increased ipsilesional knee flexion in leading position and increased variability. Increased relative muscle activity was observed in post-stroke participants with decreased variability. Mechanical work on the centre of mass seems to be the most relevant parameter to identify interlimb coordination impairments in post-stroke subjects.

Correlação entre o índice de resistência vascular e a arteriografia na avaliação do leito arterial distal na isquemia crítica dos membros inferiores / Correlation between the vascular resistance index and arteriography for assessment of the distal arterial bed in chronic limb threatening ischemia

Resumo Contexto Pacientes com isquemia crítica (IC) dos membros inferiores (MMII) precisam de arteriografia para o planejamento da cirurgia de revascularização. A ultrassonografia Doppler (UD) não é invasiva e, através da aferição do índice de resistência (IR), pode fornecer informações sobre as artérias distais. Objetivos Correlacionar a Classificação Angiográfica de Rutherford com o IR na avaliação do leito arterial distal dos MMII. Métodos Estudo transversal, realizado em hospital público terciário, com 120 pacientes portadores de IC dos MMII, entre setembro de 2019 a abril de 2022. Foi comparado o IR das artérias da perna passíveis de serem receptoras de revascularização com a imagem obtida através da arteriografia dessas artérias em acordo com a Classificação Angiográfica de leito distal de Rutherford. Resultados Foram avaliados 120 MMII em 120 pacientes com idade média de 68,6 anos. A amostra foi composta de 50,0% de pacientes do sexo masculino. Na amostra, 90,0% pacientes encontravam-se na classe cinco de Rutherford. Os valores do IR encontrados para as artérias de perna apresentaram uma correlação positiva, estatisticamente significativa, quando comparados com a Classificação de Rutherford (tibial anterior, p< 0,01; tibial posterior, p = 0,012 e fibular, p = 0,034 e artéria dorsal do pé, p < 0,001). Conclusões Neste estudo, os IRs das artérias da perna obtidos através da ultrassonografia Doppler apresentaram uma correlação positiva quando comparados à classificação de Rutherford. Em pacientes com isquemia crítica, esse índice pode ser útil na avaliação do leito arterial distal dos membros inferiores.

Abstract Background Patients with chronic limb threatening ischemia (CLTI) of the lower limbs (LL) undergo arteriography for revascularization surgery planning. Doppler ultrasound (DU) is non-invasive and can provide information about the distal arteries through measurement of the resistance index (RI). Objectives To correlate the Rutherford Angiographic Classification with the RI for assessment of the distal arterial bed of the LL. Methods A cross-sectional study, conducted at a public tertiary hospital with 120 patients with LL CLTI, from September 2019 to April 2022. The RI of arteries that were candidates for revascularization was compared with the images of the same arteries obtained using arteriography, using the Rutherford Angiographic Classification of the distal bed. Results A total of 120 LL were assessed in 120 patients with a mean age of 68.6 years. The sample was 50.0% male and 90.0% of the patients in the sample were classified as Rutherford category five. The RI values found for the arteries of the leg exhibited a statistically significant positive correlation with the Rutherford Classification (anterior tibial, p< 0.01; posterior tibial, p = 0.012 fibular, p = 0.034; and dorsalis pedis, p < 0.001). Conclusions In this study, RIs for the arteries of the leg measured using Doppler ultrasound exhibited a positive correlation with the Rutherford Classification. This index could be useful for assessment of the distal arterial bed of the lower limbs of patients with chronic limb threatening ischemia.