Active tendon

Konikoff JJ, Billings W, Nelson LJ and Hunter JM. Development of a single stage active tendon prosthesis. I. Distal end attachment. J Bone Joint Surg Am. 1974 56 848. 

An active tendon system has been examined by using a six-story steel structure [187]. Figure 8.57 shows that a control force is transmitted to the structure through diagonal braces connected to the first floor by servo-controlled hydraulic actuators. The 600 ton symmetric building, as shown, has been erected in Tokyo, Japan. In fact, two control systems has been tested on the structure (a biaxial active tendon system and a biaxial active mass damper system). 

The concept of an active tendon or bracing system, originated almost 30 years ago, has led to the successful development of the device for civil engineering structural control. 

Active devices are able to change the control force, applied to the stmctuie according to the optimal control requirements. They allow more effective control, but external energy source is required for activation of these devices. In other words, active controlled devices externally activated and apply control forces to the stmcture in order to improve its performance. Active devices include active tendons, active tuned mass dampers and actuators. 

It has been demonstrated that the stability of long-span bridges can be enhanced significantly by the application of the proposed active tendon control system. The flutter velocity of the bridge can be increased drastically, whereas the required active control force is small. Using random vibration analyses, it is further illustrated that, under strong wind... 

Active control strategies have been developed in the 1990s, (Soong 1990 Housner et al. 1997) they operate by using external energy supplied by actuators to impart forces on the structure. The appropriate control action is determined based on measurements of the structural response. Active control devices include the active tendon system (Abdel-Rohman and Leipholz 1983), the active bracing system (Reinhom et al. 1989), and the active tuned mass damper (Abdel-Rohman and Leipholz 1983). 

Preumont A (2002) Vibration control of active structures, an introduction, 2nd edn. Kluwer, The Netherlands Reinhom AM, Soong TT, Lin RC, Wang YP, Fukao Y, Abe H, Nakai M (1989) 1 4 scale model studies of active tendon systems and active mass dampers for aseismic protection, technical report NCEER-89-0026 Slotin JJ, Li W (1991) Applied non linear control. Prentice Hall, New Jersey, USA... 

The compliance in series with the active force. Force exerted by the activated elements must be transmitted or borne by whatever structural elements are in series with them. In skeletal muscle there is clearly a tendon in series but not so with smooth muscle. In smooth muscle, the total length of contractile apparatus is broken up into individual cells with intercalating extracellular connective structures. In addition, the portions of the crossbridges in series with the pulling site must also be stretched before force can rise to isometric levels. Taken together, the... 

The musculoskeletal system consists of the muscles, bones, joints, tendons, and ligaments. Disorders related to the musculoskeletal system often are classified by etiology. Acute soft-tissue injuries include strains and sprains of muscles and ligaments. Repeated movements in sports, exercise, work, or activities of daily living may lead to repetitive strain injury, where cumulative damage occurs to the muscles, ligaments, or tendons.1-3 While tendonitis and bursitis can arise from acute injury, more commonly these conditions occur as a result of chronic stress.3,4 Other forms of chronic musculoskeletal pain, such as pain from rheumatoid arthritis (see Chap. 54) or osteoarthritis (see Chap. 55), are discussed elsewhere in this text. 

In addition to minimizing the acute inflammatory response, rest prevents additional injury to the affected area.13 The properties of the muscle-tendon unit are altered during the acute injury, with limitations on the ability of the muscles and tendons to stretch. Early activity predisposes a patient to further injury, but prolonged inactivity can lengthen recovery times. 

An interneuron together with a sensory afferent and motor efferent form a polysynaptic reflex (Figure 2.2) this comprises the initial stage of information input (sensory afferent), the processing/computing an appropriate response (interneurons) and the execution of a behavioural response (motor efferent). The simplest reflexes in the nervous system are monosynaptic reflexes, such as the familiar tendon (knee) jerk, these do not involve an interneuron. The sensory afferent activated by the mechano-receptor (the tap of the patellar hammer) forms a synapse with the motor efferent in the spinal cord, which then causes the skeletal muscle to contract and the crossed leg to jerk forward. With a synaptic delay of 1 millisecond (ms), the time between input and output increases with the number of synapses introduced into the circuit. As an... 

PGA was one of the very first degradable polymers ever investigated for biomedical use. PGA found favor as a degradable suture, and has been actively used since 1970 [45 -7]. Because PGA is poorly soluble in many common solvents, limited research has been conducted with PGA-based drug delivery devices. Instead, most recent research has focused on short-term tissue engineering scaffolds. PGA is often fabricated into a mesh network and has been used as a scaffold for bone [48-51], cartilage [52-54], tendon [55, 56], and tooth [57]. 

That winter the whole inside of my parents house was painted with an oil-based paint. After that my tendons swelled, I had to wear a neck brace and I couldn t even feed myself, but we didn t realize there was a connection between the chemical exposure and my health. The tendons in my eyes were so swollen I could hardly see. It was terrifying and traumatic for me. For three years I was in bed, couldn t see anybody or do anything. It was all I could do to try to sit for a few minutes at a time. I missed my friends from college, missed school and missed my active life. I wasn t in touch with my feelings at the time. I had to stay above them or I never would have survived. 

Collagen synthesized in the absence of ascorbic acid (i.e. without hydroxyproline) cannot form its usual stable structure. Collagen is a major component of the structural and connective tissues of the body bone, cartilage, tendons, ligaments, teeth, and skin. Small wonder that things sort of fall apart in the absence of adequate ascorbic acid to support the activity of prolyl hydroxylase. 

LBP, stiff shoulder, epicondylitis and tendonitis. In soft tissue rheumatism pain at rest and/or during activity, stiffness, tenderness, and disability are the predominant features. Physical deformities are minimal but disabilities are major problems. 

Of the specific cannabinoids studied at Edgewood, pharmacologic data are available on DMHP. It was effective in producing sedation in animals at oral doses lower than 0.5 mg/kg. Several doses and routes of administration were studied, up to 1 mg/kg given intravenously. In rats, sedation occurred without initial stimulation in dogs and monkeys, hyperactivity was followed by depression and then, at higher doses, by coma. Motor effects were dramatic, in that animals developed spastic ataxia and showed extremely active deep tendon... 

Xi Xian Cao is pungent, bitter and cold, and enters the liver and Kidney meridians. It enters the deep regions of the body, the tendons and the bones. It searches out and expels wind, dampness and heat. It is selected when a Bi syndrome is at the active stage and the joints are swollen and painful with a burning sensation. Moreover, it can eliminate wind-dampness and treat heaviness and numbness of the limbs. Because it enters the Liver and Kidney meridians, Xi Xian Cao is especially effective in treating weakness and stiffness of the knees and back, pain of the bones, numbness and a tingling sensation of the limbs. 

Chlorzoxazone (Paraflex, Parafon Forte DSC, Others) [Skeletal Muscle Relaxant/ANS Drug] Uses Adjunct to rest physical therapy to relieve discomfort associated w/ acute, painful musculoskeletal conditions Action Centrally acting skeletal muscle relaxant Dose Adults. 250-500 mg PO tid-qid Peds. 20 mg/kg/d in 3-4 + doses Caution [C, ] Avoid EtOH CNS depressants Contra Severe liver Dz Disp Tabs SE Drowsiness, tach, dizziness, hepatotox, angioedema Interactions T Effects W/ antihistamines, CNS depressants, MAOIs, TCAs, opiates, EtOH, watercress EMS Use of CNS depressants and concurrent EtOH use can T sedation urine may turn reddish purple or orange OD May cause N/V/D, dizziness, HA, X deep tendon reflexes, hypotension and resp depression symptomatic and supportive, activated charcoal may be effective... 

As previously mentioned, the nickel—titanium alloys have been the most widely used shape memory alloys. This family of nickel—titanium alloys is known as Nitinol (Nickel Titanium Naval Ordnance Laboratory in honor of the place where this material behavior was first observed). Nitinol have been used for military, medical, safety, and robotics applications. Specific usages include hydraulic lines capable of F-14 fighter planes, medical tweezers, anchors for attaching tendons to bones, eyeglass frames, underwire brassieres, and antiscalding valves used in water faucets and shower heads (38,39). Nitinol can be used in robotics actuators and micromanipulators that simulate human muscle motion. The ability of Nitinol to exert a smooth, controlled force when activated is a mass advantage of this material family (5). 

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