[Chronic wounds of the lower limbs: a guide for non-specialists]. / Plaies chroniques des membres inférieurs : un guide pour le non-spécialiste.

Chronic lower-extremity ulcers are a growing public health problem, resulting in significant costs for society and patients, and having a significant impact on the quality of life of patients and informal caregivers. As general practitioners are often solicited early on, the acquisition of basic knowledge regarding wound care management is therefore essential to initiate local care, to make an early diagnosis and identify emergencies and patients that need a referral. The CASE and TIMERS frameworks enable a holistic assessment of the patient and the wound, to propose a treatment of the wound based on its etiology combined with appropriate local wound care. This framework allows also to identify atypical, severe, or recalcitrant wounds requiring specialized advice.

Les plaies chroniques des membres inférieurs sont un problème grandissant de santé publique, occasionnant des dépenses conséquentes et entraînant une répercussion non négligeable sur la qualité de vie des patients et de leurs proches aidants. Les médecins de premier recours étant le plus souvent les premiers intervenants, l'acquisition d'un socle commun de connaissances est donc essentielle pour la bonne prise en soin initiale des plaies chroniques, obtenir un diagnostic précoce et identifier les urgences et les patients à référer. L'approche selon les principes CASE et TIMERS permet une évaluation holistique du patient et de sa plaie, et de proposer un traitement étiologique associé à des soins locaux adaptés. Celle-ci permet également d'identifier les plaies atypiques, sévères ou récalcitrantes, nécessitant un avis spécialisé.

Brain-machine interface based on deep learning to control asynchronously a lower-limb robotic exoskeleton: a case-of-study.

BACKGROUND: This research focused on the development of a motor imagery (MI) based brain-machine interface (BMI) using deep learning algorithms to control a lower-limb robotic exoskeleton. The study aimed to overcome the limitations of traditional BMI approaches by leveraging the advantages of deep learning, such as automated feature extraction and transfer learning. The experimental protocol to evaluate the BMI was designed as asynchronous, allowing subjects to perform mental tasks at their own will. METHODS: A total of five healthy able-bodied subjects were enrolled in this study to participate in a series of experimental sessions. The brain signals from two of these sessions were used to develop a generic deep learning model through transfer learning. Subsequently, this model was fine-tuned during the remaining sessions and subjected to evaluation. Three distinct deep learning approaches were compared: one that did not undergo fine-tuning, another that fine-tuned all layers of the model, and a third one that fine-tuned only the last three layers. The evaluation phase involved the exclusive closed-loop control of the exoskeleton device by the participants' neural activity using the second deep learning approach for the decoding. RESULTS: The three deep learning approaches were assessed in comparison to an approach based on spatial features that was trained for each subject and experimental session, demonstrating their superior performance. Interestingly, the deep learning approach without fine-tuning achieved comparable performance to the features-based approach, indicating that a generic model trained on data from different individuals and previous sessions can yield similar efficacy. Among the three deep learning approaches compared, fine-tuning all layer weights demonstrated the highest performance. CONCLUSION: This research represents an initial stride toward future calibration-free methods. Despite the efforts to diminish calibration time by leveraging data from other subjects, complete elimination proved unattainable. The study's discoveries hold notable significance for advancing calibration-free approaches, offering the promise of minimizing the need for training trials. Furthermore, the experimental evaluation protocol employed in this study aimed to replicate real-life scenarios, granting participants a higher degree of autonomy in decision-making regarding actions such as walking or stopping gait.

Effects of releasing ankle joint during electrically evoked cycling in persons with motor complete spinal cord injury.

Literature has shown that simulated power production during conventional functional electrical stimulation (FES) cycling was improved by 14% by releasing the ankle joint from a fixed ankle setup and with the stimulation of the tibialis anterior and triceps surae. This study aims to investigate the effect of releasing the ankle joint on the pedal power production during FES cycling in persons with spinal cord injury (SCI). Seven persons with motor complete SCI participated in this study. All participants performed 1 min of fixed-ankle and 1 min of free-ankle FES cycling with two stimulation modes. In mode 1 participants performed FES-evoked cycling with the stimulation of quadriceps and hamstring muscles only (QH stimulation), while Mode 2 had stimulation of quadriceps, hamstring, tibialis anterior, and triceps surae muscles (QHT stimulation). The order of each trial was randomized in each participant. Free-ankle FES cycling offered greater ankle plantar- and dorsiflexion movement at specific slices of 20° crank angle intervals compared to fixed-ankle. There were significant differences in the mean and peak normalized pedal power outputs (POs) [F(1,500) = 14.03, p < 0.01 and F(1,500) = 7.111, p = 0.008, respectively] between fixed- and free-ankle QH stimulation, and fixed- and free-ankle QHT stimulation. Fixed-ankle QHT stimulation elevated the peak normalized pedal PO by 14.5% more than free-ankle QH stimulation. Releasing the ankle joint while providing no stimulation to the triceps surae and tibialis anterior reduces power output. The findings of this study suggest that QHT stimulation is necessary during free-ankle FES cycling to maintain power production as fixed-ankle.

The effect of Tai Chi lower extremity exercise on the balance control of older adults in assistant living communities.

BACKGROUND: Although Tai Chi (TC) is an evidence-based fall prevention training for older adults, its effective movements remain unclear, which may limit the practice of TC. The purpose of this study was to compare the effectiveness of TC lower extremity exercise (TC LEE), the 8-form Tai Chi (8-form TC), and a stretching control intervention for improving balance and functional mobility among older adults. METHODS: This was a randomized controlled trial. A total of 102 participants (79 ± 6 years old) were recruited from assisted living facilities. All participants were randomly assigned to the TC LEE (n = 40), 8-form TC (n = 31), and stretching (n = 31) groups in which they received the respective interventions for 16 weeks. The Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and center of pressure (COP) measurements during quiet stance were collected prior to and following the 16-week interventions. Comparisons on all measurements were conducted among all groups. RESULTS: Significant improvements were found in BBS (P = 0.002), TUG test (P = 0.001), root mean square amplitude of COP displacement in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions, and average COP speed in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions after training in the TC intervention groups compared with the stretching group. The upper limit of the 95% confidence interval (CI) of differences in change scores on the BBS (-0.8 - 1.3 points) between the TC LEE group and the 8-form TC group was within equivalence margins (1.8 points), while the upper limit of the 95% CI of differences in change scores on the TUG test (0.1 - 2.1 s) exceeded the equivalence margin (0.7 s) with the TC LEE group having the larger change scores. CONCLUSION: TC LEE can improve balance and functional mobility in older adults, and may have greater effect than the 8-form TC on improving functional mobility as measured by the TUG test. TRIAL REGISTRATION: ChiCTR2300070600 retrospectively registered.

The role of a community conversation intervention in reducing stigma related to lower limb lymphoedema in Northern Ethiopia.

BACKGROUND: Stigma related to lower-limb lymphoedema poses a major psychosocial burden to affected persons and acts as a barrier to them accessing morbidity management and disability prevention (MMDP) services. Community Conversation (CC), which actively engages community members and disseminates health information amongst them, is believed to break the vicious cycle of stigma by enhancing disease-related health literacy at the community level. METHODS: A quasi-experimental study was conducted in Northern Ethiopia to assess the role of the CC intervention in reducing stigma. In two control districts, a comprehensive and holistic MMDP care package was implemented that included physical health, mental health and psychosocial interventions, whilst in the intervention district the CC intervention was added to the MMDP care package. A total of 289 persons affected by lymphoedema and 1659 community members without lymphoedema were included in the study. RESULTS: Over the course of the intervention, in all sites, community members' knowledge about the causes of lymphoedema increased, and perceived social distance and stigmatizing attitudes towards people with lymphoedema decreased in the community, whilst experienced and internalized stigma decreased amongst affected persons. There were no significant changes for perceived social support. However, the changes were greater in the control sites overall, i.e. those districts in which the holistic care package was implemented without CC. CONCLUSION: The findings suggest that the CC intervention provides no additional stigma reduction when used alongside a holistic MMDP care package. Provision of comprehensive and holistic MMDP services may be adequate and appropriate to tackle stigma related to lower-limb lymphoedema in a resource-constrained setting like Ethiopia.

Health benefits of short Taichi Qigong exercise (STQE) to University Students' core strength, lower limb explosive force, cardiopulmonary endurance, and anxiety: A Quasi experiment research.

BACKGROUND: College students' physical fitness has declined over the past decades. Taichi Qigong exercise offers numerous health benefits and could serve as a suitable option for them. Traditional programs, however, are time-consuming and necessitate long-term commitments. Therefore, a more cost-effective intervention is needed. METHODS: The study enrolled a total of 31 students who actively participated in a 5-week STQE program, consisting of three 60-minute sessions per week. Physical and mental health assessments included the Plank test, vital capacity measurement, 1000/800 m run test, standing jump, and the Zung Self-Rating Scale. Data analysis was performed using SPSS. RESULTS: Following the STQE intervention, participants showed improvement in core strength (28.1 seconds in the Plank test, P = .025) and lower limb explosive force (6.52 cm in the standing jump test, P = .011), accompanied by a decrease in anxiety levels (a reduction of 3.41 in the Zung Self-Rating Scale, P = .039). However, no significant improvements were observed in cardiopulmonary endurance, as evidenced by a non-significant increase of 237.84 mL in vital capacity (P = .134) and a non-significant reduction of 1.6 seconds in the 1000/800 m run test (P = .764). CONCLUSION: The study suggests that the STQE program effectively improves core strength, lower limb explosive force, and reduces anxiety levels among university students.

Evaluation of the relationship between truss/windlass mechanisms and foot stiffness while walking.

BACKGROUND: The truss/windlass coefficients ware reported as a surrogate parameter for foot stiffness while walking. However, the construct validity and reliability of whether the truss/windlass coefficients reflect foot stiffness have not been sufficiently validated. This study validated the truss/windlass coefficient reflects the construct validity and reliability of foot stiffness. METHODS: Participants were 25 healthy young males (21.6 ± 0.7 years). Foot stiffness was assessed using Simplified Foot Stiffness. It was determined by dividing the difference in foot load between sitting and standing by the rate of change in navicular height. The truss/windlass coefficient was calculated as the behavior of the foot arch during middle to late stance. To assess the reliability of each parameter, intraclass correlation coefficients (ICC 1.1) and Bland-Altman analysis were used, and Spearman's rank correlation coefficients were used to determine construct validity. RESULTS: The truss coefficient (ICC1.1 0.86) and Simplified Foot Stiffness (ICC1.1 0.87) demonstrated high reliability and no systematic error. However, the windlass coefficient (ICC1.1 0.73) demonstrated moderate reliability and proportional error. Furthermore, the truss coefficient had a significant positive correlation with Simplified Foot Stiffness (r = 0.504; p < 0.01), whereas the windlass coefficient did not (r = 0.06; p = 0.67). CONCLUSION: The truss coefficient was proposed as a highly reliable parameter that reflects foot stiffness. However, the windlass coefficient has a proportional error, despite being moderately reliable.

Effectiveness of instrument assisted soft tissue mobilization versus foam rolling on trigger point release in calf muscles.

BACKGROUND: Instrument assisted soft tissue mobilization and foam rolling are two techniques that have been proven effective in treating Myofascial Trigger Points, irrespective of the type of trigger point. However, little is known about the comparative effectiveness of Instrument assisted soft tissue mobilization and foam rolling. This study proposed to evaluate the effectiveness of either technique on plantar flexors trigger points, ankle dorsiflexion, and lower limb power present in the calf muscles in non-symptomatic patients. METHOD: Forty-two subjects with bilateral calf muscle tightness, at least one trigger point in the calf muscle, and fulfilling the inclusion criteria were randomly assigned to either of the groups. Group A was treated for gastrocnemius and soleus trigger points using Instrument assisted soft tissue mobilization and Group B was treated using the Foam Rolling method. Treatment was given every alternate day, a total of 3 sessions. Subjects were evaluated on 1st and 3rd sessions for pre-post differences of ankle dorsiflexion Range of motion in weight bearing and non-weight bearing position, pressure pain threshold for gastrocnemius trigger point 1(G1), 2(G2), and soleus point 1(S1) on both sides, and lower limb power. RESULT: Within group analyses, both groups had shown statistically significant results for all parameters except gastrocnemius trigger point 2 of foam rolling. For between group comparison foam rolling had a statistically significant result in non-weight bearing ankle dorsiflexion range of motion. CONCLUSION: Both Instrument assisted soft tissue mobilization and Foam rolling were equally effective for treating calf trigger points. But foam rolling was more effective in improving ankle dorsiflexion range of motion.

The effect of lower back and lower-extremity kinesiology taping on static balance and physical function performance in people with multiple sclerosis: A pilot study.

INTRODUCTION: Multiple sclerosis (MS) can lead to numerous deficits in body functions, including balance and mobility impairment. This study examined the effect of lower back and lower extremity kinesiology tape (KT) application on static balance and physical functioning performance in people with MS (pwMS) and compared that to a non-elastic tape. METHODS: This pilot randomized study recruited and enrolled 10 participants with MS that were allocated into two groups: kinesio (n = 6) and non-elastic (n = 4) tape. Participants were assessed with and without the respective tape on static balance with eyes open and closed and various physical function tests. RESULTS: Effect sizes for the Kinesio tape intervention were found to be small, while effect sizes for the sham tape/place condition varied from small to high. For both groups, the tendency was to reduce or maintain performance on the tests comparing tape and no tape. A subsequent, mixed-factor ANOVA revealed no significant difference between KT or sham tape/placebo. CONCLUSION: Our findings suggest that KT applied on lower back and lower extremity muscles does not seem to improve static balance and physical function performance in pwMS.

Combined effect of myofascial release and passive stretching on plantar pressure in individual with hamstring tightness- an experimental study.

INTRODUCTION: The lower kinetic chain is known to be affected by hamstring tightness which causes biomechanical alterations. As per the literature, short hamstring might cause prolonged forefoot loading, which can cause higher repeated stress on the plantar fascia. There is evidence supporting the use of various stretching and myofascial release techniques for hamstring tightness, further research is needed to investigate their impact on plantar pressure. Hence the study aims to determine combined effect of myofascial release and passive stretching on plantar pressure in individual with hamstring tightness. METHODS: This was an experimental pre-post study design with 67 randomised screenings from asymptomatic health care science students aged 18 to 25. From this scientific survey, a sample size of 47 students having HMS tightness based on the popliteal angle were recruited using a universal goniometer. An intervention was proposed that included MFR and passive stretching in 3 sessions on alternate days. Plantar pressure of these individuals was noted by using the "Harris and Beath foot printing mat" before and after the intervention. RESULT: Significant pressure changes were observed after intervention: great toe of right side (p = 0.001), toes 2 to 5 of right side (p = 0.010) and left side (p = 0.008), first metatarsal of left side (p = 0.010), lateral forefoot of right side (p = 0.019) and left (p = 0.018), medial heel (p = 0.044), and lateral heel of right side (p = 0.025). These values substantiate the enhancement in plantar pressure. CONCLUSION: The combined effect of Myofascial release and passive stretching in an individual with hamstring tightness resulted in a significant increase in popliteal angle and plantar pressure.

Can photobiomodulation improve quadriceps strength and endurance outcomes in asymptomatic adults? A double-blind randomized controlled trial.

AIM: To explore the effect of photobiomodulation on quadriceps strength and endurance torques in asymptomatic adults. METHODS: Twenty-eight asymptomatic adults were randomized to one of two interventions: photobiomodulation (n = 14) or sham (n = 14). Quadriceps strength was evaluated by maximum voluntary isometric contraction test (60°) and endurance by an elastic resistance in multiple-set knee extension/flexion repetitions using a traction dynamometer. The outcomes were measured at three time points: pre-baseline; baseline and; final assessment. The photobiomodulation was applied to the quadriceps and triceps surae muscles of each participant's dominant lower limb, using a cluster with 1 infrared laser diode and 3 led amber of 170 mW for 240 s over four consecutive days. The sham group went through the same procedures, but the equipment was off, and patients and assessors were blinded to the intervention. Reliability and minimal detectable change of the measures were obtained from the pre-baseline and baseline time points. Differences between interventions were tested by an analysis of covariance. RESULTS AND DISCUSSION: There was no difference between photobiomodulation compared to sham in maximum isometric torque (mean difference (95% CI) = 0.008 (-0.29 to 0.31) and endurance torques (mean difference (95% CI) = 0.04 (-0.03 to 0.12). The mean difference was lower than the minimal detectable change for the maximum isometric torque (1.02 Nm.kg-1) and endurance torque (0.49 Nm.kg-1). CONCLUSION: Photobiomodulation does not improve quadriceps strength and endurance outcomes in asymptomatic adults.

Effect of acupuncture combined with lower limb gait rehabilitation robot on improving walking function in stroke patients with hemiplegia.

BACKGROUND: No study has yet demonstrated the effect of lower limb gait rehabilitation robot treatment combined with acupuncture on stroke patients. OBJECTIVE: To explore the effect of acupuncture combined with lower limb gait rehabilitation robot on walking function in patients with hemiplegia after stroke. METHODS: Fifty-six patients with hemiplegia after stroke were enrolled and randomly divided into two groups. The control group received regular rehabilitation training and acupuncture therapy; the intervention group was additionally trained by AiWalker-I lower limb gait robot. Both groups received 5 sessions a week for 4 weeks. Walking function parameters were assessed before and after the 4-week treatment. RESULTS: There was no significant difference in all parameters between the two groups in baseline (P > 0.05). After 4 weeks of treatment, all parameters including the effectiveness of functional ambulation category (FAC), time up and go test (TUGT) time, Wisconsin gait scale (WGS) score, walking spatiotemporal parameters were all significantly improved in both groups with a significant better effect in the intervention group (P < 0.05). CONCLUSION: Acupuncture combined with lower limb gait rehabilitation robot training has a positive effect on correction of abnormal gait and improvement of walking ability of hemiplegic patients after stroke.

Cone-Beam CT of the Extremities in Clinical Practice.

Cone-beam CT (CBCT) is a promising tool with increasing applications in musculoskeletal imaging due to its ability to provide thin-section CT images of the appendicular skeleton and introduce weight bearing, which accounts for loading forces that typically interact with and affect this anatomy. CBCT devices include an x-ray source directly opposite a digital silicon detector panel that performs a single rotation around an object of interest, obtaining thin-section images. Currently, the majority of research has been focused on the utility of CBCT with foot and ankle pathologic abnormalities, due to the complex architectural arrangement of the tarsal bones and weight-bearing nature of the lower extremities. Associated software can provide a variety of options for image reconstruction, including metal artifact reduction, three-dimensional biometric measurements, and digitally reconstructed radiographs. Advancements in this technology have allowed imaging of the knee, hip, hand, and elbow. As more data are published, it is becoming evident that CBCT provides many additional benefits, including fast imaging time, low radiation dose, lower cost, and small equipment footprint. These benefits allow placement of CBCT units outside of the traditional radiology department, including the orthopedic clinic setting. These technologic developments have motivated clinicians to define the scope of CBCT for diagnostics, surgical planning, and longitudinal imaging. As efforts are made to create standardized protocol and measurements, the current understanding and surgical approach for various orthopedic pathologic conditions will continue to shift, with the hope of improving outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Self-Massage Acute Effects on Pressure Pain Threshold, Muscular Electrical Activity, and Muscle Force Production: A Systematic Review and Meta-Analysis.

ABSTRACT: Furlan, MR, Machado, E, Petter, GdN, Barbosa, IM, Geremia, JM, and Glänzel, MH. Self-massage acute effects on pressure pain threshold, muscular electrical activity, and muscle force production: a systematic review and meta-analysis. J Strength Cond Res 38(3): 620-635, 2024-Self-massage (SM) is often used in physiotherapy and sports training programs. However, the SM acute effects on pressure pain threshold (PPT), muscle electrical activity (MEA), and muscle force production remain unclear. A meta-analytical review was performed to verify the SM acute effects on neuromuscular responses in healthy adults or athletes. The review (CRD42021254656) was performed in the PubMed, Web of Science, and Embase databases. A synthesis of the included studies was performed, and both the risk of bias and the evidence certainty level were assessed through the PEDro scale and Grading of Recommendations Assessment, Development, and Evaluation approach, respectively. Nineteen studies were included, 5 evaluated the PPT, 7 the thigh muscles' MEA, and 15 the lower-limb strength. The SM application induces moderate increases in quadriceps' PPT (5 studies; standardized mean difference [SMD]: 0.487; 95% CI 0.251-0.723; p < 0.001; I2 = 0%). We found no SM effects on the hamstrings and plantar flexors' MEA. Also, we observed small increases in knee extensors' concentric torque (2 studies; SMD: 0.288; 95% CI 0.088-0.489; p = 0.005; I2 = 0%), without effects in isometric muscle strength, eccentric torque, and rate of force development. Grading of recommendations assessment, development, and evaluation analysis showed high and low certainty levels for the SM effects on quadriceps' PPT and muscle strength, respectively. Self-massage pressure-volume application seems to be a determining factor in inducing changes in these parameters, and it may vary among the treated muscles, where a higher pressure-volume application is required for increasing knee flexors and plantar flexors' PPT and strength. Thus, new studies with better methodological quality should be performed to strengthen this evidence.

Action observation with motor simulation improves reactive stepping responses following strong backward balance perturbations in healthy young individuals.

BACKGROUND AND OBJECTIVE: Adequate reactive steps are critical for preventing falls following balance perturbations. Perturbation-based balance training was shown to improve reactive stepping in various clinical populations, but its delivery is labor-intensive and generally uses expensive equipment. Action observation of reactive steps with either motor imagery (AOMI) or motor simulation (AOMS) are potential alternative training modalities. We here aimed to study their effects on reactive stepping performance. METHODS: Sixty healthy young subjects were subjected to forward platform translations that elicited backward reactive steps. The AOMI group (n = 20) was tested after AOMI of an actor's reactive steps, while the AOMS group (n = 20) additionally stepped along with the actor. The control group (n = 20) was tested without any prior observation. Our primary outcome was the step quality of the first trial response, as this best represents a real-life loss-of-balance. Step quality was quantified as the leg angle with respect to the vertical at stepping-foot contact. We also studied single step success rates and reactive step quality across repeated trials. RESULTS: Reactive step quality was significantly better in the AOMI and AOMS groups than in the control group, which differences coincided with a twofold higher single step success rate. Reactive step quality improved upon repeated trials in all groups, yet the AOMS group needed the fewest repetitions to reach plateau performance. SIGNIFICANCE: The present results demonstrate that both AOMI and AOMS improved first and repeated trial reactive stepping performance. These findings point at the potential applicability of these concepts for home-based reactive balance training, for instance in serious games, with overt movements (AOMS) possibly having some benefits over mental imaginations (AOMI). Whether similar beneficial effects also emerge in the target populations of balance-impaired individuals remains to be investigated.

The Effect of Multidimensional Spiritual Psychotherapy on the Quality of Life of Bone Cancer Survivors with a History of Lower Extremity Amputation.

INTRODUCTION: This study aimed to investigate the effect of multidimensional spiritual psychotherapy on anxiety, depression, and attitude towards self and god in bone cancer patients after amputation. METHOD: Forty one cancer patients with a history of Below-The-Knee amputation were recruited in this quasi-experimental study. The design included pre-and post-tests in experimental and control  groups. The experimental group received 15 sessions of multidimensional spiritual psychotherapy. Cattell Anxiety Inventory (CAI), Beck Anxiety Inventory (BAI), Beck's Depression Inventory (BDI), Religious Adherence Questionnaire (RAQ), and Self-concept-God concept questionnaire were administered for data collection. RESULTS: There was a significant difference between the control and experimental groups in terms of anxiety (P=0.0001), Depression (P=0.0001), God-image (P=0.035, F(1,38)=4.79), God-concept (P=0.006, F(1,38)=8.58), self-image (P=0.0001, F(1,38)=98.62), and self-concept (P=0.0001, F(1,38)=120.56), psychological evolution (P=0.0001, F(1,38)=19.36), and religious adherence (P=0.0001, F(1,38)=84.21). CONCLUSION: The results of the study indicated that the emphasis on spirituality and the implementation of spiritual care could improve the cancer amputated patients' well-being.

First-in-human demonstration of floating EMG sensors and stimulators wirelessly powered and operated by volume conduction.

BACKGROUND: Recently we reported the design and evaluation of floating semi-implantable devices that receive power from and bidirectionally communicate with an external system using coupling by volume conduction. The approach, of which the semi-implantable devices are proof-of-concept prototypes, may overcome some limitations presented by existing neuroprostheses, especially those related to implant size and deployment, as the implants avoid bulky components and can be developed as threadlike devices. Here, it is reported the first-in-human acute demonstration of these devices for electromyography (EMG) sensing and electrical stimulation. METHODS: A proof-of-concept device, consisting of implantable thin-film electrodes and a nonimplantable miniature electronic circuit connected to them, was deployed in the upper or lower limb of six healthy participants. Two external electrodes were strapped around the limb and were connected to the external system which delivered high frequency current bursts. Within these bursts, 13 commands were modulated to communicate with the implant. RESULTS: Four devices were deployed in the biceps brachii and the gastrocnemius medialis muscles, and the external system was able to power and communicate with them. Limitations regarding insertion and communication speed are reported. Sensing and stimulation parameters were configured from the external system. In one participant, electrical stimulation and EMG acquisition assays were performed, demonstrating the feasibility of the approach to power and communicate with the floating device. CONCLUSIONS: This is the first-in-human demonstration of EMG sensors and electrical stimulators powered and operated by volume conduction. These proof-of-concept devices can be miniaturized using current microelectronic technologies, enabling fully implantable networked neuroprosthetics.

Effects of ankle exoskeleton assistance and plantar pressure biofeedback on incline walking mechanics and muscle activity in cerebral palsy.

Ankle dysfunction affects more than 50 % of people with cerebral palsy, resulting in atypical gait patterns that impede lifelong mobility. Incline walking requires increased lower limb effort and is a promising intervention that targets lower-limb extensor muscles. A concern when prescribing incline walking to people with gait deficits is that this exercise may be too challenging or reinforce unfavorable gait patterns. This study aims to investigate how ankle exoskeleton assistance and plantar pressure biofeedback would affect gait mechanics and muscle activity during incline walking in CP. We recruited twelve children and young adults with CP. Participants walked with ankle assistance alone, biofeedback alone, and the combination while we assessed ankle, knee, and hip mechanics, and plantar flexor and knee extensor activity. Compared to incline walking without assistance or biofeedback, ankle assistance alone reduced the peak biological ankle moment by 12 % (p < 0.001) and peak soleus activity by 8 % (p = 0.013); biofeedback alone increased the biological ankle moment (4 %, p = 0.037) and power (19 %, p = 0.012), and plantar flexor activities by 9 - 27 % (p ≤ 0.026); assistance-plus-biofeedback increased biological ankle and knee power by 34 % and 17 %, respectively (p ≤ 0.05). The results indicate that both ankle exoskeleton assistance and plantar pressure biofeedback can effectively modify lower limb mechanics and muscular effort during incline walking in CP. These techniques may help in establishing personalized gait training interventions by providing the ability to adjust intensity and biomechanical focus over time.

Thermo-haemodynamic coupling during regional thigh heating: Insight into the importance of local thermosensitive mechanisms in blood circulation.

A positive relationship between local tissue temperature and perfusion exists, with isolated limb-segment hyperthermia stimulating hyperaemia in the heated region without affecting the adjacent, non-heated limb segment. However, whether partial-limb segment heating evokes a heightened tissue perfusion in the heated region without directly or reflexly affecting the non-heated tissues of the same limb segment remains unknown. This study investigated, in 11 healthy young adults, the lower limb temperature and haemodynamic responses to three levels of 1 h upper-leg heating, none of which alter core temperature: (1) whole-thigh (WTH; water-perfused garment), (2) quadriceps (QH; water-perfused garment) and (3) partial-quadriceps (PQH; pulsed shortwave diathermy) heating. It was hypothesised that perfusion would only increase in the heated regions. WTH, QH and PQH increased local heated tissue temperature by 2.9 ± 0.6, 2.0 ± 0.7 and 2.9 ± 1.3°C (P < 0.0001), respectively, whilst remaining unchanged in the non-heated hamstrings and quadriceps tissues during QH and PQH. WTH induced a two-fold increase in common femoral artery blood flow (P < 0.0001) whereas QH and PQH evoked a similar ∼1.4-fold elevation (P ≤ 0.0018). During QH and PQH, however, tissue oxygen saturation and laser-Doppler skin blood flow in the adjacent non-heated hamstrings or quadriceps tissues remained stable (P > 0.5000). These findings in healthy young humans demonstrate a tight thermo-haemodynamic coupling during regional thigh heating, providing further evidence of the importance of local heat-activated mechanisms on the control of blood circulation.