Epidemiological and Clinical Pattern of Open Fractures of Long Bones of the Lower Limbs in the South-West Region of Cameroon: A 5-Year Review

Background: An open fracture is an injury in which the fracture site and/or hematoma communicates with the external environment. It is associated with significant morbidity and disability and is a challenge to the surgical team. The lower extremities are the most often exposed to traumatic injuries compared to other anatomical parts of the body. Patterns of open fractures differ with different mechanisms of injury and the segment of the long bone affected. The correct and timely management of open fractures is beneficial to the patients and leads to a more favorable outcome. This study aimed at describing the pattern of open fractures of long bones of the lower limb treated in 3 major hospitals of the south west region, Cameroon. Methodology: This was a hospital-based retrospective review of files of patients with open fractures of long bones of the lower limb managed at the surgical units of three secondary health facilities in the South-West region of Cameroon from the 1st of January 2015 to the 31st of December 2019. The socio-demographic characteristics, clinical presentation, treatment modalities, and outcomes were recorded. The data was stored and analyzed using Epi info version 7.0 and SPSS version 23.0 respectively. Results: A total of 195 files of patients aged 8 to 80 years were studied. The main age group affected was between 20 - 40 years. There were 147 (75.4%) males and 48 (24.6%) females giving a sex-ratio of 3.1:1. The most common cause was road traffic crashes 142 (72.8%). In 98 cases (50.3%), the left side was more involved. The tibia was the most common long bone affected in 75 (38.5%) cases. Comminuted fracture was the most common fracture pattern encountered in 126 cases (64.6%). A total of 76 (39%) fractures were graded Gustilo-Anderson IIIA. External fixator was used in 112 cases (57.1%) and internal fixator in 86 cases (42.9%). We recorded 127 (65.1%) cases of wound infection and 143 (73.3%) cases of limb shortening as the most common complications. Other complications include: 20 cases (17.1%) of mal-union, 27 cases (22.5%) of delayed union, 18 cases (15.1%) of non-union and 50 cases (38.5%) chronic osteomyelitis. We recorded a mortality of 2.1%. Gustilo IIIB and IIIC were associated to chronic osteomyelitis (P = 0.02). Conclusion: Open fractures of long bones of the lower limb affect the active age group of the population and road traffic crashes are the most common causes. It tends to affect the left side and the tibia being the most fractured long bone. A reasonable proportion of these fractures subsequently get infected. Comminuted fracture is the common fracture pattern.

Effects of Hip Arthroplasties on Bone Adaptation in Lower Limbs: A Computational Study

Gait disorders contribute to the risk of falls and successive injuries, especially to elderly populations. The risk of falls becomes higher for hip osteoarthritis (OA) and hip arthroplasties patients due to poor balancing and gait impairment. Bone adaptation and bone loss are fundamental issues in considering the changes of bone behavior and gait pattern. In this study, computational analysis of the lower limbs was conducted to estimate the bone adaptation after hip arthroplasties procedure. 3D inhomogeneous model of lower limb was developed from computed topography (CT- based) data of 79 years old patient with hip osteoarthritis problem in left limb. Two types of arthroplaties were constructed in the left limb, namely total hip arthroplasty and resurfacing hip arthroplasty using commercial biomedical software, Mechanical Finder v6.1. Prosthesis stem and acetabular cup of THA were modelled as titanium alloy material (E = 114 GPa, v = 0.34), femoral ball and bearing insert as alumina properties (E = 370 GPa, v = 0.22). Meanwhile, RHA implant was assigned as Co-Cr-Mo material (E = 230 GPa, v = 0.30). Contact between both implants and bone were considered to be perfectly bonded at the interface. A load case of quiet standing position was conducted in this analysis with 60 kg of the patients’ body weight. The load was applied at the cross sectional lumbar vertebra and fixed at the distal of femoral shafts. Results show different patterns of stress distribution in right and left (operated) limbs for hip OA, THA and RHA models. An indication of stress alteration on both limbs after arthroplasties suggested that the bone adaptation occurred. The higher percentage of change in the left limb projected that the adaptation was more critical in operated limb.

Neural Network Robust Control Based on Computed Torque for Lower Limb Exoskeleton

The lower limb exoskeletons are used to assist wearers in various scenarios such as medical and industrial settings.Complex modeling errors of the exoskeleton in different application scenarios pose challenges to the robustness and stability of its control algorithm.The Radial Basis Function(RBF)neural network is used widely to compensate for modeling errors.In order to solve the problem that the current RBF neural network controllers cannot guarantee the asymptotic stability,a neural network robust control algorithm based on computed torque method is proposed in this paper,focusing on trajectory tracking.It innovatively incorporates the robust adaptive term while introducing the RBF neural network term,improving the compensation ability for modeling errors.The stability of the algorithm is proved by Lyapunov method,and the effectiveness of the robust adaptive term is verified by the simulation.Experiments wearing the exoskeleton under different walking speeds and scenarios were carried out,and the results show that the absolute value of tracking errors of the hip and knee joints of the exoskeleton are consistently less than 1.5°and 2.5°,respectively.The proposed control algorithm effectively compensates for modeling errors and exhibits high robustness.

Model Parameters Identification and Backstepping Control of Lower Limb Exoskeleton Based on Enhanced Whale Algorithm

Exoskeletons generally require accurate dynamic models to design the model-based controller conveniently under the human-robot interaction condition.However,due to unknown model parameters such as the mass,moment of inertia and mechanical size,the dynamic model of exoskeletons is difficult to construct.Hence,an enhanced whale optimization algorithm(EWOA)is proposed to identify the exoskeleton model parameters.Meanwhile,the periodic excitation trajectories are designed by finite Fourier series to input the desired position demand of exoskeletons with mechanical physical constraints.Then a backstepping controller based on the identified model is adopted to improve the human-robot wearable comfortable performance under cooperative motion.Finally,the proposed Model parameters identification and control are verified by a two-DOF exoskeletons platform.The knee joint motion achieves a steady-state response after 0.5 s.Meanwhile,the position error of hip joint response is less than 0.03 rad after 0.9 s.In addition,the steady-state human-robot interaction torque of the two joints is constrained within 15 N·m.This research proposes a whale optimization algorithm to optimize the excitation trajectory and identify model parameters.Furthermore,an enhanced mutation strategy is adopted to avoid whale evolution’s unsatisfactory local optimal value.

Personalized Lower Limb Gait Reconstruction Modeling Based on RFA-ProMP

Personalized gait curves are generated to enhance patient adaptability to gait trajectories used for passive training in the early stage of rehabilitation for hemiplegic patients.The article utilizes the random forest algorithm to construct a gait parameter model,which maps the relationship between parameters such as height,weight,age,gender,and gait speed,achieving prediction of key points on the gait curve.To enhance prediction accuracy,an attention mechanism is introduced into the algorithm to focus more on the main features.Meanwhile,to ensure high similarity between the reconstructed gait curve and the normal one,probabilistic motion primitives(ProMP)are used to learn the probability distribution of normal gait data and construct a gait trajectorymodel.Finally,using the specified step speed as input,select a reference gait trajectory from the learned trajectory,and reconstruct the curve of the reference trajectoryusing the gait keypoints predictedby the parametermodel toobtain the final curve.Simulation results demonstrate that the method proposed in this paper achieves 98%and 96%curve correlations when generating personalized lower limb gait curves for different patients,respectively,indicating its suitability for such tasks.

Simple bone cysts of the proximal humerus presented with limb length discrepancy:A case report

BACKGROUND Simple bone cysts(SBC)are benign tumor-like bone lesions typically identified in children.While SBC may lead to growth disturbances or growth arrest,such cases are uncommon.The mechanisms behind these observations remain unclear.Additionally,research on the etiology of SBC remains inconclusive,and there has been no consensus on the appropriate timing and methodology for treatment.CASE SUMMARY Here,we present our experience in the successful surgical management of a 10-year-old girl with SBC,who presented with a pathological fracture complicated by malunion of the displaced fracture,varus deformity,and limb length discrepancy.We hypothesized two possible etiologies for the patient’s growth arrest and subsequent humerus varus deformity:(1)Direct disruption of the physis by fluid from the cyst itself;and(2)damage to the epiphysis due to repetitive pathological fractures associated with SBC.In addressing this case,surgical intervention was undertaken to correct the proximal humerus varus deformity.This approach offered the advantages of simultaneously correcting angular abnormalities,achieving mild limb lengthening,providing definitive SBC treatment,and reducing the overall treatment duration.CONCLUSION As per current literature,acute correction of acute angular deformity in proximal humeral SBC is not well comprehended.However,in this specific case,acute correction was considered an optimal solution.

Epidemiological, Clinical and Paraclinical Profile of Osteoarthritis of the Lower Limbs in Obese Patients at the Cocody University Teaching Hospital

Objective: To describe the epidemiological, clinical and paraclinical characteristics of osteoarthritis of the lower limbs in obese patients at the Cocody University Teaching Hospital. Methodology: This was an analytical cross-sectional study carried out in the rheumatology department of the Cocody UTH in Abidjan (Ivory Coast) from March 1 to April 30 2023. Patients who came for rheumatology consultation presenting with mechanical arthralgia of the lower limbs, who were obese, had radiographic images were included. All patients without radiographic images were excluded. Obesity was defined as a body mass index (BMI) greater than or equal to 30 kg/m. The Chi2 test was used to compare proportions and determine the existence of associations between osteoarthristis and obesity, obesity severity and radiographic stage of osteoarthritis as well as the functional impact. A p-value below a predefined threshold (p = 0,05) indicates a significant relationship between the variables. Result: Out of 185 patients received for osteoarthritis of the lower limbs during the study period, 136 were obese (74%). There were 115 women (84.6%) with an average age of 56.03 with a standard deviation of 12.72 years (extremes: 22 and 84 years). The main socio-professional category was the informal sector (30%). The majority of patients had a low socio-economic level (80.2%) and lived in urban areas (92.6%). The most common past medical history was hypertension (33.08%) followed by peptic ulcer disease (16.91%). Patients had a body mass index class 1 (81.6%), class 2 (15.40%) and class 3 (2.90%). The average duration of symptom progression until diagnosis was 11 months. Genu varum was the main static disorder (56.10%) and the knee joint was the dominant topography (90.4%) with a bilateral localization (80%). The average Lequesne index was greater than 8 (59.5%). The Kellgren and Lawrence radiographic stages were stage 1 (9.20%), stage 2 (46.90%), stage 3 (29.20%) and stage 4 (6.90%). The Obesity severity was significantly associated with osteoarthritis of the knee (p = 0.042). There was no statistically significant association between obesity severity and radiographic stage of osteoarthritis (p = 0.163) or functional impact (p = 0.180). Conclusion: Osteoarthritis of the lower limbs affected obese women and was dominated by stage 2 osteoarthritis of the knee (Kellgren and Lawrence). There is an association between the severity of obesity and osteoarthritis of the knee.

Intervention Effect of Lower Limb Rehabilitation Robot with Task-Oriented Training on Stroke Patients and Its Influence on KFAROM Score

Objective: To explore the effect of lower limb rehabilitation robot combined with task-oriented training on stroke patients and its influence on KFAROM score. Methods: 100 stroke patients with hemiplegia admitted to our hospital from January 2023 to December 2023 were randomly divided into two groups, the control group (50 cases) was given task-oriented training assisted by nurses, and the observation group (50 cases) was given lower limb rehabilitation robot with task-oriented training. Lower limb balance, lower limb muscle strength, motor function, ankle function, knee flexion range of motion and walking ability were observed. Results: After treatment, the scores of BBS, quadriceps femoris and hamstrings in the observation group were significantly higher than those in the control group (P Conclusion: In the clinical treatment of stroke patients, the combination of task-oriented training and lower limb rehabilitation robot can effectively improve the lower limb muscle strength, facilitate the recovery of balance function, and have a significant effect on the recovery of motor function, which can improve the walking ability of stroke patients and the range of motion of knee flexion, and achieve more ideal therapeutic effectiveness.

Assistive Devices and Clothing: Exploring Adaptive Clothing Needs for Women with Lower Limb Prostheses Using the FEA Model

This study aimed to comprehensively investigate the essential considerations in designing adaptive clothing for women with lower limb prostheses in Saudi Arabia. Employing a qualitative methodology, the research entailed semi-structured, in-depth interviews with women utilizing lower limb prostheses and prosthetic specialists. This approach was selected to unearth pivotal design prerequisites and comprehend the specific challenges these women encounter within the realm of clothing. The utilization of selective sampling facilitated the collection of intricate and valuable insights. A Functional, Expressive, and Aesthetic (FEA) User Needs model was utilized to scrutinize participant feedback. Functional requisites encompass ease of dressing and undressing, accessibility to the prosthetic limb, comfort, mobility with the prosthesis, and appropriate fit. Additionally, participants highlighted various expressive needs, including privacy preservation, modesty, camouflaging disability appearances, maintaining alignment with non-disabled women’s fashion, and considerations about the aesthetic aspects of garments.

A Clinical Randomized Controlled Study of Low-Frequency rTMS Therapy on Lower Limb Motor Dysfunction after Stroke

Objective:To investigate the efficacy and safety of low-frequency repetitive transcranial magnetic stimulation(rTMS)for the treatment of lower limb motor dysfunction after stroke.Methods:A total of 96 patients with stroke and lower limb motor dysfunction were enrolled in this study,and were randomly divided into the experimental group and the sham stimulation group using the method of calculator-generated random numbers.Both groups received conventional medication and rehabilitation therapy.The experimental group received 4 weeks of 1 Hz rTMS treatment in the primary cortical motor area(M1)of the healthy side,with the treatment coil tangent to the skull surface;the sham stimulation group underwent the same procedures as the experimental group,but the treatment coil was perpendicular to the skull surface instead.Lower-extremity subscale of the Fugl-Meyer Assessment(FMA-LE),Berg Balance Scale(BBS),gait analysis,and lower-extremity surface electromyography(LESEM)were performed in both groups before and after rTMS treatment.Results:All 96 patients completed the test with no shedding and no adverse reactions.After treatment,the FMA-LE score and BBS score of the 2 groups of patients were significantly improved as compared with the pre-treatment(P<0.05),and the TUG test time was reduced as compared with the pre-treatment(P<0.05).The true stimulation group had greater improvement in all assessment indexes than that of the sham stimulation group(P<0.05).After treatment,the electromyographic activity of the tibialis anterior and rectus femoris muscles in the true simulation group improved significantly.The step length,step speed,and step frequency were also significantly improved in both groups after treatment,and the symmetrical ratio of step length and support time was reduced(P<0.05).Comparison between the groups revealed that the true simulation group significantly improved after rTMS treatment as compared to the sham stimulation group(P<0.05).Conclusion:1Hz rTMS treatment safely and effectively improved motor and balance function in patients with post-stroke lower limb motor dysfunction.

Clinical Effectiveness of the Plate Screw Internal Fixation Technique in the Treatment of Patients with Traumatic Fractures of Long Bones in the Lower Extremities

Objective: To investigate the effectiveness of the plate screw internal fixation technique on the clinical outcomes of patients with traumatic fractures of long bones in the lower extremities. Methods: From January 2022 to December 2023, 70 patients with traumatic fractures of long bones in the lower extremities were admitted to the hospital and randomly divided into two groups: the control group and the observation group, each consisting of 35 cases. The control group underwent traditional closed interlocking intramedullary nailing, while the observation group received internal fixation with steel plates and screws. Relevant surgical indicators, treatment effectiveness, and postoperative complication rates were compared between the two groups. Results: The observation group exhibited significantly short surgical duration (80.65 ± 5.01 vs. 88.36 ± 5.26 minutes), fracture healing time (13.27 ± 0.32 vs. 15.52 ± 0.48 weeks), and hospitalization days (10.49 ± 1.13 vs. 16.57 ± 1.15 days) compared to the control group (P = 0.000). The effective treatment rate was significantly higher in the observation group (29/82.86%) than in the control group (21/60.00%), with a significant difference observed (χ2 = 4.480, P = 0.034). Additionally, the complication rate in the observation group (2/5.71%) was significantly lower than that in the control group (8/22.86%), with a correlated difference (χ2 = 4.200, P = 0.040). Conclusion: The plate screw internal fixation technique demonstrates significant clinical efficacy in treating traumatic fractures of long bones in the lower extremities. It improves the healing rate, reduces complications, and represents a safe and effective treatment strategy worthy of widespread use and application.

Lower limb amputation rehabilitation status in India: A review

Rehabilitation of lower limb amputation in developing countries is quite challenging.Though there are basic to highly advanced prostheses available in India,the set-up is still facing difficulties in developing countries.Prosthetic management is difficult due to lack of availability of prostheses and reduced affordability among low income populations.In this review we highlighted the lower limb amputation and prosthetic rehabilitation status in India.Currently,India is advancing well in the rehabilitation field,but further studies are required to provide more evidence and recommendation.

Indication and surgical approach for reconstruction with endoprosthesis in bone-associated soft tissue sarcomas:Appropriate case management is vital

It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follow-up,in terms of the management of these cases.Some STS are associated with bone and major neurovascular structures.Bone-associated STS are generally relatively large and relatively deep-seated.Additionally,the tendency for metastasis is high.In some cases,the decision about which structures to resect is difficult.These cases are often accompanied by poor oncological and surgical outcomes.Management of cases should be done by a multidisciplinary team in advanced centers specialized in this field.The surgical team must have sufficient knowledge and experience in the field of limb-sparing surgery.Preoperative evaluation and especially good planning of bone and soft tissue reconstruction are vital.

Equalisation of Lower Limb Length in Young Adults Using Internal Osteosynthesis: A Case Report of 22 Patients

Introduction: Inequality in the length of the lower limbs has an impact on the stability and function of the musculoskeletal system because of the imbalance it causes in our bodies. Several treatment modalities were used by practitioners. The aim of this study was to evaluate the anatomical and functional results of length equalisation of the lower limbs using internal osteosynthesis in the Orthopaedic and Traumatological Surgery Department of the Amirou Boubacar Diallo National Hospital in Niamey. Patients and method: This was a retrospective, prospective study of 22 patients from January 2010 to November 2015, a period of 5 years. The patients concerned were aged at least 18 years and had undergone a femoral shortening osteotomy not exceeding 5 cm on the contralateral healthy limb with a screw plate as the internal osteosynthesis device. Results: The average age of our patients was 24.18 years (18 to 48 years). The etiologies of these length inequalities were: vascular 54.55% (n = 12), post-traumatic 27.27% (n = 6), post-infectious 13.64% (n = 3) and neuromuscular 4.54% (n = 1). The mean length inequality of our patients was 4.93 cm, with extremes ranging from 4 to 8 cm. At an average follow-up of 6.5 months (6 to 24 months), our functional results were satisfactory overall. Discussion: Despite the significant nature of our initial inequalities, which were moderate and severe, we ended up with slight inequalities or even total correction for some of our patients. Conclusion: Inequality in the length of the lower limbs is a handicap that requires appropriate management.

Knowledge of Patients and Their Accompanying Persons about Obliterative Arteriopathy of the Lower Limbs at Conakry University Hospital in 2022

Introduction: Obliterative arterial disease of the lower limbs is a marker of advanced atherosclerosis. It is one of the world’s most common cardiovascular diseases, present in one in five people over the age of 60, and carries an increased risk of morbidity and mortality. The aim of this study was to assess the knowledge of patients and their carers about obliterative arteriopathy of the lower limbs at Conakry University Hospital. Material and Methods: We conducted a descriptive cross-sectional study lasting 3 months, from March 12 to June 12, 2022 in the hospitals of the University Hospital of Conakry (Donka and Ignace Deen). Following free and informed consent, they were interviewed on the basis of a pre-established questionnaire. Socio-demographic data (age, gender, level of education) were collected, and knowledge of obliterative arterial disease of the lower limbs. Results: The study involved 159 people, comprising 106 patients (66.66%) and 53 accompanying persons (33.34%) in the hospitals of the University Hospital of Conakry (Donka and Ignace Deen). The 60 to 79 age group was the most represented (44.7%), with an average age of 55.4 ± 15.9 years and extremes of 20 to 84 years. Half (47.8%) had not attended school, and almost all (96.4%) of those who had attended school had a low level of education (primary and secondary). Almost all of them (91.2%) had never heard of AOMI. Only 5% identified at least one risk factor, diabetes, hypertension and smoking. Amputation was the most frequently identified complication. About 98% did not know that AOMI is associated with myocardial infarction and stroke, and 93.7% did not know of any complications. Almost all the participants (99.4%) had poor knowledge of the following complications. Conclusion: Obliterative arterial disease of the lower limbs could be prevented or delayed by screening and controlling risk factors. Our results show a huge deficit in knowledge of this pathology, including risk factors, preventive measures, clinical signs and complications among patients and their relatives. A study conducted outside the hospital environment would provide a better understanding of the extent to which the general population is unaware of this disease.

The effectiveness of the mononuclear fraction of autologous bone marrow in the treatment of experimental chronic limb ischemia

Objective To study of the effectiveness of using autologous mononuclear fraction of bone marrow for the treatment of chronic limb ischemia. Methods Results of autologous mononuclear fraction of bone marrow in 90 laboratory Wistar rats on a background of creating chronic limb ischemia was presented. Sampling was carried out from the bone marrow of the femur of the animal. The mononuclear fraction of bone marrow autologous 4 × 106 cells in a volume of 200 microliter were injected into the ischemic limb of the two points,in each of which 100 microliter:(1)Paravessel directly below the inguinal ligament at the level of the sacroiliac joint in the area of the anatomical location of collaterals in the projection of the internal iliac artery and its branches;(2)Intramuscularly in gastrocnemius muscle anterior-lateral surface of the middle third of the leg. Results In the experimental group of rats treated with autologous mononuclear fraction of bone marrow,the level of microcirculation compared with the intact group of animals on day 21 was higher than 6. 1% by day 28% ~ 31. 2%; compared with the control group-day 10 increased by 111% at day 21,85. 7% on day 28% ~ 97%. Conclusion Proposed method of treating pathogenically justified and can be recommended for use in clinical practice in the treatment of patients with chronic obliterating diseases of lower limb arteries.

Structure Design of Lower Limb Exoskeletons for Gait Training

Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patients. Correlatively, in kinematics the exoskeletons are required to be compatible with human lower limbs and thereby to avoid the uncontrollable interactional loads at the human-machine interfaces. Such requirement makes the structure design of exoskeletons very difficult because the human-machine closed chains are complicated. In addition, both the axis misalignments and the kinematic character difference between the exoskeleton and human joints should be taken into account. By analyzing the DOF（degree of freedom） of the whole human-machine closed chain, the human-machine kinematic incompatibility of lower limb exoskeletons is studied. An effective method for the structure design of lower limb exoskeletons, which are kinematically compatible with human lower limb, is proposed. Applying this method, the structure synthesis of the lower limb exoskeletons containing only one-DOF revolute and prismatic joints is investigated; the feasible basic structures of exoskeletons are developed and classified into three different categories. With the consideration of quasi-anthropopathic feature, structural simplicity and wearable comfort of lower limb exoskeletons, a joint replacement and structure comparison based approach to select the ideal structures of lower limb exoskeletons is proposed, by which three optimal exoskeleton structures are obtained. This paper indicates that the human-machine closed chain formed by the exoskeleton and human lower limb should be an even-constrained kinematic system in order to avoid the uncontrollable human-machine interactional loads. The presented method for the structure design of lower limb exoskeletons is universal and simple, and hence can be applied to other kinds of wearable exoskeletons.

Versatility of Reverse Sural Fasciocutaneous Flap for Reconstruction of Distal Lower Limb Soft tissue Defects

Summary： In this study we present our experiences with the reverse sural fasciocutaneous flap to reconstruct the distal lower limb soft tissue defects caused by traumatic injuries. These flap graftings were carried out from Oct. 2010 to Dec. 2012 in our department. The series consisted of 36 patients, including 21 men and 15 women with an average age of 46.2 years （14-83 years） and with a medium followp period of 18 months （12-24 months）. Of all the cases of acute trauma, there were 10 eases of trauma of distal tibia, 9 cases of trauma of perimalleolus, and 17 cases of trauma of midfoot and forefoot. Related risk factors in the patients were diabetes （2 cases）, advanced age （〉65 years, 3 cases） and ciga- rette smoking （6 cases）. The reverse flow sural island flap irrigation depended on lower perforators of the peroneal artery. The fasciocutaneous pedicle was 3-4 cm in width and the anatomical structures consisted of the superficial and deep fascia, the sural nerve, short saphenous vein, superficial sural artery together with an islet of subcutaneous cellular tissue and skin. The most proximal border of the flap was only 1.5 cm away from the popliteal skin crease and the pivot point was 5-7 cm above the tip of the lateral malleolus. All the flaps survived. No arterial crisis occurred in any case. The venous congestion occurred in 2 cases and got better after raising the limbs and bloodletting. Only in an old man, 1.5 cm necrosis of distal margin of his flap occurred and finally healed after continuous dressing change. One-stage skin grafting was performed, and all the donor sites were sutured and successfully healed. It was concluded that the reverse sural fasciocutaneous flap is safe and reliable to extend to the proximal third even near the popliteal skin crease. We also concluded this flap can be safely and efficiently used to treat patients with large and far soft-tissue defects from the distal leg to the forefoot with more versatility and it is easier to reach the recipient sites.

Control and Implementation of 2-DOF Lower Limb Exoskeleton Experiment Platform

In this study,a humanoid prototype of 2-DOF(degrees of freedom)lower limb exoskeleton is introduced to evaluate the wearable comfortable effect between person and exoskeleton.To improve the detection accuracy of the humanrobot interaction torque,a BPNN(backpropagation neural networks)is proposed to estimate this interaction force and to compensate for the measurement error of the 3D-force/torque sensor.Meanwhile,the backstepping controller is designed to realize the exoskeleton's passive position control,which means that the person passively adapts to the exoskeleton.On the other hand,a variable admittance controller is used to implement the exoskeleton's active followup control,which means that the person's motion is motivated by his/her intention and the exoskeleton control tries best to improve the human-robot wearable comfortable performance.To improve the wearable comfortable effect,serval regular gait tasks with different admittance parameters and step frequencies are statistically performed to obtain the optimal admittance control parameters.Finally,the BPNN compensation algorithm and two controllers are verified by the experimental exoskeleton prototype with human-robot cooperative motion.

Investigation of blood pulse PPG signal regulation on toe effect of body posture and lower limb height

Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.