The sciatic nerve (SN) is the largest peripheral nerve in the body. Normally, it exits from the pelvis through the greater sciatic foramen and passes under the piriformis muscle (PM). PM is a triangular shaped muscle which is located on the ventral surface of sacrum and sacrotuberous ligament and runs diagonally downwards to insert on the greater trochanter (GT) . After the SN passes under PM, it travels between GT and ischial tuberosity(IT) toward the back of thigh. The SN bifurcates into tibial (TN) and common fibular nerve (CFN) usually at the apex of the popliteal fossa. SN serves an important role in controlling muscles of the back of the thigh, leg and foot. It also receives sensation from the skin of entire lower leg, as well as the foot. Furthermore, it provides articular branches to the joints of lower limb [8, 20].
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The anatomical studies of the piriformis muscle reported in the literature did not contribute to make a real correlation between the clinical signs and the anat- omy and to describe the different anatomical forms for the same syndrome. A study  involving 240 cadaver dissections has revealed that in 90 percent of cases the sciatic nerve emerges from below the piriformis muscle, in 7 percent the piriformis and the sciatic are divided, one branch of the sciatic nerve passing through the split and the other branch passing distal to the muscle, in 2 percent only the sciatic nerve is divided and in 1 percent the piriformis is divided by the sciatic nerve. Pecina M. found that in 6.15% of cases, the nervous peroneus com- munis passes between the tendinous parts of m. pirifor- mis, and he considers this variation of practical significance for the development of the Piriformis Syn- drome . After reviewing the cadaveric anatomical variants of the literature [3,19] and surgical anatomical descriptions [5,20-22], we demonstrated three anatomi- cal observations in our series (Fig. 2,3,4), but they did not add further information on the anatomical variants and their clinical expressions.
He did a study on the effects of three types of Piriformis muscle stretching on muscle thickness and the medial rotation angle of the coxal articulation. A study includes a total of 45 subjects who participated in the study randomly allocated into three groups: stretching with flexion of coxal articulation over ( SFCO ) 90°,stretching with flexion of coxal articulation under (SFCU) 90°, and MET application. For the SFCO, the subjects bent two legs in a supine position and put the leg of one side on the opposite side knee that would be measured. The subjects bent their knee over 90° until they felt tension in the direction toward the shoulder on the same side as the leg that was being stretched and then maintained the position for 30 seconds. This was repeated twice with a 30-seconds resting time in between. For the SFCU, the leg that would be stretched was crossed over the opposite side knee in a supine position. The subjects touched the outside of the knee toward the ground for 30seconds.This was repeated twice with a 30- second resting time in between. The study concluded that Stretching improves physical performance ability, prevents injury, and reduces muscle pain and increases flexibility.
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The authors present an anatomical basis and physiologic reason for the presenting symptoms and several methods of treating piriformis syndrome. The symptoms are be- lieved to be the result of contractures in the piriformis muscle with an increase in the diameter which presses on the nerves and vessels as they pass through the greater sciatic foramen. The authors mention the “piriformis sign” which is external rotation of the involved leg with the patient in the prone position. They also described a unique sign, deepening of the sulcus (because of the sacrum mov- ing anterior) with a rotoscoliosis and increased lordosis. They explain females may have painful intercourse and males may experience impotence because the pudendal blood vessel supply is compressed by the contracture in the piriformis muscle. The authors write that the primary fo- cus in treating piriformis syndrome should be to relieve the contracture.
Clinically, pain due to PMPS can be aggravated by compression of the MTrP of piriformis muscle, and the pain can be referred to the posterior thigh. In addition, the PMPS pain can also be elicited or aggravated by compression or any irritation (provoking test) to the etiological lesion site, such as the sacroiliac joint, the subtrochanteric bursa, or the lumbar facet joint. Lumbar facet lesions are probably the most common extrinsic causes of PMPS. In such cases, the pain can be reproduced during performance of a lumbar facet test, 23,24 and the pain can be relieved by appropriate treatment
Piriformis syndrome is a questionable entity that has been cited as a cause of buttock pain and sciatica. It has been implicated as a potential source of pain and dysfunction, not only in general population but in athletes as well (Carter 1988; Kuland 1988). Piriformis syndrome is said to occur more commonly in women. The often quoted sex ratio of 6:1 is derived from Pace & Nagle’s series published in 1976 (Pace J and Nagel D 1976). The literature reported that atleast 6% of patients actually suffered with piriformis syndrome who are initially diagnosed with low back pain (Papedopeulos et al 1990; Hallin 1983). The key elements of the piriformis syndrome are the anatomical relationships of the piriformis muscle to the sciatic nerve. The piriformis originates from the anterior aspect of the sacral vertebra 2 through 4 and inserts on the greater trochanter. The sciatic nerve typically exits the greater sciatic notch just below the inferior border of the piriformis muscle (Benzon et al 2003; Fishman et al 2002). In about 7% to 20%
to the gluteal tuberosity. The medial part of the muscle was reflected. The deep surface of the muscle was watched carefully to avoid injury to the posterior cutaneous nerve of the thigh. The inferior gluteal vessels and the nerve was found entering the lower part of the muscle and the superficial parts of the superior gluteal vessels entering its upper part, as the ischial tuberosity was uncovered the bursae was superficial to the origin of the hamstring muscles from the tuberosity. The muscle was detached from the surface of the rigid Sacro tuberous ligament, and the perforating cutaneous nerves were found.The relation between the Sciatic nerve and piriformis muscle was noted 13 .
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The occurrence in women is greater than in men. One pos- sible explanation of this could be the wider pelvis in wom- en, leading to coxa vara. This must be imposing additional strain to the piriformis muscle even on single leg stance when the muscle stabilizes the hip. Piriformis syndrome is characterized by radiating pain from the sacro-lumbar region to the buttocks and down to the lower limb. The causes of sciatica usually relate to degenerative changes in the spine and lesions to the inter vertebral discs . There are two types of piriformis syndrome—primary and secondary. Primary piriformis syndrome has an anatomic cause, such as a split piriformis muscle, split sciatic nerve, or an anomalous sciatic nerve path. Secondary piriformis syndrome occurs as a result of a precipitating cause, in- cluding macrotrauma, microtrauma, ischemic mass effect, and local ischemia. Among patients with piriformis syn- drome, fewer than 15% of cases have primary causes. Piriformis syndrome occurs most frequently during the fourth and fifth decades of life and affects individuals of all occupations and activity levels .
Standard textbooks of anatomy reported the muscle to be frequently absent. The frequency of psoas minor muscle in human beings is probably influenced by ethnic and racial characteristics (7). Morphology of psoas minor also varies with its frequency. In a study by Rickenbacker, Landholt and Theiler (1985), psoas minor muscle was absent in 50% of individuals. Anson (1966) reported the muscle to be absent in 41% of adult individuals while Williams (1995) found that this percentage could be over 50% (14,15,16). In our study, the frequency of absence was as high as 60%
The experimental group received kinesiology taping on diaphragm in a muscle facilitation approach. This resulted in better activation of the diaphragm due to cutaneous sensorimotor stimulation of the diaphragm, as kinesiology taping improved the muscle activation. Zubeyir S. et al stated that Kinesiology Taping on the diaphragm can help in re-educating the diaphragm for working efficiently as a chief inspiratory muscle.  Also, Huang C. et al in a study in 2011 on kinesiology taping on medial gastrocnemius found a significant increase on muscle activity on EMG. This was mainly due to better proprioceptive stimulation and recruitment of the muscles due to kinesiology taping. [12,13] Also, Kalantari K. et al in a study on kinesiology taping on the extensor aspect of the forearm found a significant increase in grip strength. This improvement was found mainly due to better recruitment of the muscle fibres. 
Our data from MCP treated rats indicates that the energy charge of the skeletal muscle was not decreased when rats were completely paralysed but decreased 2.5 hours after poisoning in comparison to controls. The high-energy charge of the muscle maintained over the course of poisoning, as well as during periods of both severe and persisting muscle weakness, indicate that the muscle was able to maintain sufficient ATP for energy dependent biosynthetic reactions to be carried out. The data indicate that bioenergetic failure does not seem to play a role in initiating muscle weakness following MCP poisoning in rats, as ATP levels and energy charge were normal in paralyzed muscle. However, it is possible that these parameters are affected as a consequence of paralysis, since low ATP levels and decreased energy charge were noted only in the immediate aftermath of poisoning and subsequently returned to normal even though muscle weakness persisted. As humans have prolonged muscle weakness, a role for persistent inhibition of ATP synthesis and low energy charge in contributing to muscle weakness in humans cannot be ruled out. However, all the data so far indicates that the initiating trigger for muscle paralysis could be upstream of ATP levels per se and hence we focused on mitochondrial ATP synthesis directly to elucidate the mechanism of muscle weakness after MCP. As an initial step in this direction, the integrity of muscle mitochondria after MCP poisoning was evaluated by examination of mitochondrial swelling characteristics.
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I declare that this report entitle “Motion Control of Pneumatic Muscle Actuator: Experimental Setup and Modeling” is the result of my own research except as cited in the references. The report has not been accepted for any degree and is not concurrently submitted in candidature of any other degree.
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when using joystick the movement used both hands to grip the stick, but only the right hand are used to move, especially the thumb. The thumb on the right hand move actively when running virtual robotic manufacturing system with rotating direction while the other fingers didn't move, maximum movement of the thumb make the flexor pollicis brevis muscle has a strongest contraction.
Muscle aging, known as sarcopenia, is significant problem in terms of quality of life, health, and decreased life expectancy. Muscle aging studies and muscle aging animal models are required since human life is of considerable length, making examinations very difficult. In this study, we used the SAMP8 for a sarcopenia model animal. First, we examined muscle mass and muscle strength changes following a habitual exercise program. Guo et al. reported that SAMP8 muscle mass peaked at 7 months old and muscle strength decline began at 8 months old; therefore, we used 28 weeks old (7 months old) SAMP8 . Relative gastrocnemius muscle mass decreased with aging (Figure 3-B). Additionally, muscle strength decreased in the 44w group. These results were consistent with previous studies , and both aspects are important since EWGSOP refers to sarcopenia as not only a decrease in muscle mass, but also a decline in muscle strength. Although the absolute weights tended to be significant, there was no significant difference. This point was different from previous studies. Liu et al. reported that fat accumulates in SAMP8’s muscles with aging . Hence, ectopic fat may have accumulated in this study. Additionally, differences in breeding environment affected the amount of physical activity, etc., and there may have been no clear difference in changes in muscle weight. Nevertheless, it is useful to be able to evaluate the effects of aging on muscles in a short period of time, so SAMP8 is a useful model animal for sarcopenia.
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is limited in that it cannot evaluate the association of each muscle property with diabetes or osteoporosis. In the present study, we used QCT and performance tests to analyze not only muscle CSA but also muscle composition and perfor- mance, which are closely related to functional impairment and disability. According to our study, muscle CSA, strength, and physical performance were not associated with insulin resis- tance, whereas muscle HU value was significantly associated with insulin resistance: subjects with lower HU value in mus- cle, which means more fat infiltration, showed higher insulin resistance. Therefore, our present findings implicate persis- tently damaged muscles accompanied by fatty infiltration in the development of insulin resistance. Several studies have explored the association of sarcopenia with muscle adiposity and insulin resistance. 29-31 Cell death processes occur in re-
Many animals use elastic recoil mechanisms to power extreme movements, achieving levels of performance that would not be possible using muscle power alone. Contractile performance of vertebrate muscle depends strongly on temperature, but the release of energy from elastic structures is far less thermally dependent, thus elastic recoil confers thermal robustness to whole-animal performance. Here we explore the role that muscle contractile properties play in the differences in performance and thermal robustness between elastic and non-elastic systems by examining muscle from two species of plethodontid salamanders that use elastically powered tongue projection to capture prey and one that uses non-elastic tongue projection. In species with elastic mechanisms, tongue projection is characterized by higher mechanical power output and thermal robustness compared with tongue projection of closely related genera with non-elastic mechanisms. In vitro and in situ muscle experiments reveal that species differ in their muscle contractile properties, but these patterns do not predict the performance differences between elastic and non- elastic tongue projection. Overall, salamander tongue muscles are similar to other vertebrate muscles in contractile performance and thermal sensitivity. We conclude that changes in the tongue- projection mechanism, specifically the elaboration of elastic structures, are responsible for high performance and thermal robustness in species with elastic tongue projection. This suggests that the evolution of high-performance and thermally robust elastic recoil mechanisms can occur via relatively simple changes to morphology, while muscle contractile properties remain relatively unchanged.
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! (! Exercise may allow the changes in muscle mass and oxidative capacity, as well as the free-radical damage, that occur with age to be slowed or even reversed. Exercise has been shown to increase muscle mass (Westerterp 2000), muscle oxidative capacity (Cartee 1994; Westerterp 2000) and antioxidant defenses against free-radical damage (Lands, Grey et al. 1999). Any intervention that is able to increase the rate of muscle protein synthesis could reverse losses in muscle mass and oxidative capacity, and restore muscle function. Importantly, it seems that resistance training, in particular, may play a crucial role in the prevention of sarcopenia (Johnston, De Lisio et al. 2008). Indeed, one study demonstrated that three months of high-intensity resistance exercise training significantly stimulated the in vivo rate of muscle protein synthesis in the vastus lateralis of individuals aged between 76 and 92 years (Yarasheski, Pak-Loduca et al. 1999). Regular resistance training, therefore, is thought to be a potentially valuable intervention in helping to prevent age-related loss of muscle mass and strength.
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therefore many researchers employed a generic musculoskeletal geometry model established with reported data collected from cadavers to calculate muscle-tendon length and moment arm. However, the generic musculoskeletal geometry may not suitable for specific individuals and subject-specific musculoskeletal geometry is essential for the improvement of moment prediction accuracy. To match the specific subject, the geometry path can be scaled based on relative distances between pairs of markers obtained from a motion-capture system. However, the motion-capture system is quite expensive. A practical solution is proposed here to tackle this problem. For simplicity, the muscles are assumed as straight lines. 17 Since the muscle path can be affected by the size
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Meanwhile, other hypotheses indicate that greater increases in serum CK activity after EIMD were associated with a shorter Tc, a measure of estimated MHC-I proportion. More precisely, deceased Tc values indicate higher fast-twitch muscle fibre proportion. For example, the esti- mated VL MHC-I proportion (extracted from the linear combination of contraction time, delay time and half-relaxation time) decreased by –8.2% (p=0.041) in parallel with decreased Tc, as a result of eight weeks of plyometric training . Also, Macaluso et al.  reported micro trauma of predominantly type II fibres following a sin- gle bout of plyometric training. Increased CK lev- els and damaged fibres around the sarcolemma and the sarcomere (at the site of the Z-disc) were found. Substantial metabolic demands during excessive exercise may be coupled with a structural disadvantage (e.g., thinner and argu- ably weaker Z-discs), subsequently resulting in an increased risk of greater damage to type II muscle fibres . The correlation between averaged Tc of all investigated muscles, previously found to be related to type I fibres , and the CK level was significant (r s = –0.70, p=0.03). This finding poses
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The flexor digitorum superficialis (FDS) muscle in adults is composed of several muscle slips that accumu- late in a 3-dimensional manner. Figure 2 shows these slips after slight dissection for 2-dimensional extension. The muscle slip arrangement of FDS muscles varies widely and can include absence of a tendon to the fifth finger [4, 14, 20]. The basic double-layered configura- tion consists of a deep layer containing muscle slips for the second and third fingers and regarded as a digastric configuration, and a superficial layer comprised of slips for the third and fourth fingers. Although the intermedi- ate tendon cannot be visualised by the surface view, the masked intermediate tendon always connects a deep muscle slip for the second finger to the distal parts of the FDS muscle [14, 20]. These findings suggested that a nerve branch to the second finger muscle slip (ramus superior ) originates from the median nerve at a site distant from the others (rami medius and inferior) and that the former branch is likely bundled with a nerve to the palmaris longus muscle.