Lower Limb Structure, Function, and Locomotion Biomechanics

2012 ◽  
pp. 265-298
Author(s):  
William Ledoux ◽  
Michael Hahn
Keyword(s):  
Structure Function ◽  
Lower Limb ◽  
Limb Structure

Kinematics study of a 10 degrees-of-freedom lower extremity exoskeleton for crutch-less walking rehabilitation

2021 ◽  
pp. 1-9
Author(s):  
Jingshuai Liu ◽  
Yong He ◽  
Feng Li ◽  
Wujing Cao ◽  
Xinyu Wu
Keyword(s):  
Lower Extremity ◽  
Lower Limb ◽  
Degrees Of Freedom ◽  
Leg Extension ◽  
Closed Form Solutions ◽  
Kinematic Characteristics ◽  
Movement Characteristics ◽  
Movement Performance ◽  
Walking Rehabilitation ◽  
Limb Structure

BACKGROUND: Wearable lower extremity exoskeletons can provide walking assistance for the physical rehabilitation of paralyzed individuals. However, most of the existing exoskeletons require crutches to maintain balance, thus a self-balancing type is needed to improve applicability. OBJECTIVE: The purpose of this work is to study the kinematic characteristics of a novel lower extremity exoskeleton for crutch-less walking rehabilitation, and evaluate the movement performance through practical experiments. METHODS: Based on the human lower limb structure and movement characteristics, a fully actuated 10 degrees-of-freedom (DoF) lower extremity exoskeleton was proposed. The kinematic characteristics of the exoskeleton were analyzed by the D-H method and geometric method, and the model validity was verified through simulations and experiments. RESULTS: The closed-form solutions for both forward and inverse kinematics models were obtained. The consistent results of theoretical calculation and numerical simulation have shown the accuracy of the established models. The practical experiments regarding six trials have demonstrated the movement performance of the proposed exoskeleton, including sit, stance, leg extension/flexion, and left/right swing. CONCLUSIONS: The kinematic characteristics of the proposed 10-DoF lower extremity exoskeleton are similar to the human lower limb, and it could meet the motion demands of crutch-less walking rehabilitation.

The chronically ischemic lower limb

JAMA ◽  
1966 ◽  
Vol 197 (11) ◽  
pp. 915-916
Author(s):  
I. J. Schatz
Keyword(s):  
Lower Limb

Cardiac troponin I in patients with acute upper and lower limb ischemia

VASA ◽  
2008 ◽  
Vol 37 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Koutouzis ◽  
Sfyroeras ◽  
Moulakakis ◽  
Kontaras ◽  
Nikolaou ◽  
...  
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Cardiac Troponin ◽  
Cardiac Involvement ◽  
Troponin I ◽  
Limb Ischemia ◽  
Elevated Troponin ◽  
Troponin Elevation ◽  
Lower Limb Ischemia ◽  
Ischemia Group

Background: The aim of this study was to investigate the presence, etiology and clinical significance of elevated troponin I in patients with acute upper or lower limb ischemia. The high sensitivity and specificity of cardiac troponin for the diagnosis of myocardial cell damage suggested a significant role for troponin in the patients investigated for this condition. The initial enthusiasm for the diagnostic potential of troponin was limited by the discovery that elevated cardiac troponin levels are also observed in conditions other than acute myocardial infarction, even conditions without obvious cardiac involvement. Patients and Methods: 71 consecutive patients participated in this study. 31 (44%) of them were men and mean age was 75.4 ± 10.3 years (range 44–92 years). 60 (85%) patients had acute lower limb ischemia and the remaining (11; 15%) had acute upper limb ischemia. Serial creatine kinase (CK), isoenzyme MB (CK-MB) and troponin I measurements were performed in all patients. Results: 33 (46%) patients had elevated peak troponin I (> 0.2 ng/ml) levels, all from the lower limb ischemia group (33/60 vs. 0/11 from the acute upper limb ischemia group; p = 0.04). Patients with lower limb ischemia had higher peak troponin I values than patients with upper limb ischemia (0.97 ± 2.3 [range 0.01–12.1] ng/ml vs. 0.04 ± 0.04 [0.01–0.14] ng/ml respectively; p = 0.003), higher peak CK values (2504 ± 7409 [range 42–45 940] U/ml vs. 340 ± 775 [range 34–2403] U/ml, p = 0.002, respectively, in the two groups) and peak CK-MB values (59.4 ± 84.5 [range 12–480] U/ml vs. 21.2 ± 9.1 [range 12–39] U/ml, respectively, in the two groups; p = 0.04). Peak cardiac troponin I levels were correlated with peak CK and CK-MB values. Conclusions: Patients with lower limb ischemia often have elevated troponin I without a primary cardiac source; this was not observed in patients presenting with acute upper limb ischemia. It is very important for these critically ill patients to focus on the main problem of acute limb ischemia and to attempt to treat the patient rather than the troponin elevation per se. Cardiac troponin elevation should not prevent physicians from providing immediate treatment for limb ischaemia to these patients, espescially when signs, symptoms and electrocardiographic findings preclude acute cardiac involvement.

Acute limb ischemia in a patient with pre-fibrotic myelofibrosis complicated by heparin-induced thrombocytopenia and thrombosis – case report and systematic review of dabigatran use

VASA ◽  
2020 ◽  
pp. 1-6 ◽  
Author(s):  
Marina Di Pilla ◽  
Stefano Barco ◽  
Clara Sacco ◽  
Giovanni Barosi ◽  
Corrado Lodigiani
Keyword(s):  
Systematic Review ◽  
Case Report ◽  
Lower Limb ◽  
Limb Ischemia ◽  
Acute Limb Ischemia ◽  
Review Of The Literature ◽  
Heparin Induced Thrombocytopenia ◽  
Lower Limb Ischemia ◽  
Vein Thrombosis ◽  
Left Lower Limb

Summary: A 49-year-old man was diagnosed with pre-fibrotic myelofibrosis after acute left lower-limb ischemia requiring amputation and portal vein thrombosis. After surgery he developed heparin-induced thrombocytopenia (HIT) with venous thromboembolism, successfully treated with argatroban followed by dabigatran. Our systematic review of the literature supports the use of dabigatran for suspected HIT.

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