Forearm muscles

FIGURE 18.14 With NMR spectroscopy one can observe the metabolism of a living subject in real time. These NMR spectra show the changes in ATP, creadne-P (phosphocre-adne), and P levels in the forearm muscle of a human subjected to 19 minutes of exercise. Note that the three P atoms of ATP a, /3, and y) have different chemical shifts, reflecting their different chemical environments. 

T. Kutsuzawa, S. Shioya, D. Kurita and M. Haida, Deoxygenated hemoglobin/myoglobin kinetics of forearm muscle from rest to exercise in patients with chronic obstructive pulmonary disease. Tohoku ]. Exp. Med., 2009, 217,9-15. 

P NMR spectra of human forearm muscle showing the effect of exercise. A Before exercise B and C during 19 minutes of exercise D 5-6 minutes after C. Peak assignments 1, /3-phosphorus of ATP 2, -phosphorus of ATP 3, y-phosphorus of ATP 4, phosphocreatine 5, Pi. Phosphocreatine is used as a major source of energy during exercise. It is hydrolyzed to creatine and Pi. Note that the level of ATP remains relatively constant during exercise because it is produced and used at about the same rate. After G. Radda, Science 233, 641 (1986). Reprinted with permission from the American Association for the Advancement of Science. 

Clinical symptoms from TOCP intoxication were similar first symptoms occurred about 1 to 3 weeks following ingestion of the poison usually with calf pain. This progressed within days to weakness, followed by ataxia and distal paralysis. Proximal paralysis and sometimes hand and forearm muscle involvement, occurred in more severe cases. 

Among other predictions, the integrated model reveals that as work rate is varied, commensurate increases in the rate of mitochondrial ATP synthesis are effected by changes in concentrations of available ADP and inorganic phosphate. In other words, mitochondrial respiratory control is achieved in vivo by substrate feedback control. The predicted relationship between substrates and work rate is plotted in Figure 7.14. Model predictions are compared to data obtained from NMR spectroscopy of exercising flexor forearm muscle in healthy human subjects [106],... 

J. A. Jeneson, H. V. Westerhoff, T. R. Brown, C. J. Van Echteld, and R. Berger. Quasi-linear relationship between Gibbs free energy of ATP hydrolysis and power output in human forearm muscle. Am. J. Physiol., 268 C1474-1484, 1995. 

Hagenfeldt, L., and Wahren, J. (1971), Human forearm muscle metabolism during exercise, Scand- J. Clin. Lab. invest. 27,299-306. 

Garland DE, Tilling M, Keenan MA. Percutaneous phenol blocks to motor points of spastic forearm muscles in head-injured adults. Arch Phys Med Rehabil 1984 65(5) 243-5. 

D) had lower levels of glycogen in biopsies of her forearm muscle... 

A relatively new approach to nutrition assessment is to evaluate muscle function as an end-organ response. Hand-grip strength (forearm muscle dynamometry), respiratory muscle strength, and muscle re-... 

Figure 12.14 Effect of anaerobic exercise on NMR spectra of human forearm muscle. 

Peckham and colleagues [24] at Case Western Reserve University used chronic percutaneous stimulation of forearm muscles to provide hand grasp, including both palmar and lateral prehension and release, in C5 quadriplegic patients. 

Another illustration of the application of MRS is provided by the P spectra of human forearm muscle, taken before and during exercise. Both spectra show resonance peaks characteristic of CP, ATP and orthophosphate ions (Pi). A comparison of peak intensities indicates considerable changes of CP and P, while the ATP content remains nearly constant [64]. 

Avulsion fractures of the medial epicondyle are seen between the ages of 9 and 15, after the apophysis becomes a separate ossification nucleus from the epiphysis of the distal humerus and before it fuses with the distal humerus. The medial epicondyle is a traction apophysis for the flexor group of forearm muscles, and also serves as an attachment for the ulnar collateral ligaments and the joint capsule. This injury accounts for up to 10% of elbow fractures. 

Fig. 7. Nuclear magnetic resonance spectroscopy. Use of nmr to show the effect of exercise on the levels of creatine phosphate, ATP and orthophosphate in human forearm muscle P nmr spectra of (a) resting muscle and (b) muscle after 19 minutes of exercise. Adapted from G.K.Radda Science 233 (1986) 640-645.

Other biologically important nuclei with spin are P, Na, and F. Instrumentation has been developed for studying NMR spectra of intact human and animal body parts. For example, P spectra of human forearm muscle... 

B. R. Soller, J. Sliwa, Y. Yang, F. Zou, K. L. Ryan, C. A. Rickards, and V. A. Convertino, Simultaneous Spectroscopic Determination of Forearm Muscle pH and Oxygen Saturation during Simulated Haemorrhage, /. Near Infrared Spectros., 20,141 (2012). 

Juha Oksa et al, 2002) 8 Male/mean 31 years 25°C and 5°C Forearm blood flow during systemic cooling was significantly lower. Repetitive work in the cold causes higher muscular activity and fatigue of forearm muscles than in thermo-neutral conditions. 

Contract your forearm muscles statically. Hold for a count of 4 seconds, relax. 

Examination There are muscle fasciculations in the right arm and forearm, and left thigh and calf. The right arm and forearm muscles were moderate weak and atrophic. He has slight-moderate weakness of his right hand muscles. There is a slight proximal left lower-limb weakness and a left foot drop. AH tendon reflexes were absent or prominently reduced. The plantar responses were flexor on the right and not applicable on the left due to toe weakness. Sensory examination and cranial nerves were normal. 

Carry MR, Horan SB, Reed SM et al. (1993) Structure, innervation, and age-associated changes of mouse forearm muscles. Anat Ree 237(3), 345-357. 

The electrodes are disposable plate ones which are suitable for this experiment. All data sets are captured from forearm muscle and force is recorded from the wrist of target. The sample rate of data sampling was 2000 hertz which is suitable for EMG signal. Sampling rate of force signal has been chosen the same to have a good and easy comparison between measured and simulated force signal. 

The researcher explained all the procedures of the task to be performed to the subjects before every testing. The subjects sat on the standard office chair and the computer was placed on the standard computer table. They were instructed to carry out the typing activity for 30 seconds prior to the measurement of first trial to ensure that all the signals registered correctly [9]. The subjects were instructed to type at their optimal speed, a given test paragraph, in order to standardize the muscle activation of measured forearm muscle. The full methodology flow chart is shown in Fig. 2. 

Struthers , which joins the anomalous bony process and the medial epicondyle. Clinically, this condition typically affects young sportsmen as a result of intense muscular activity in the elbow and forearm and may start with pain and numbness in the first three fingers and weakness of forearm muscles innervated by the median nerve (Sener et al. 1998). US can demonstrate the relationship of the median nerve with the anomalous bone and ligament. Although not yet reported in the radiological literature, displacement of the nerve by these structures may represent an indicator of entrapment. Therapy includes excision of the ligament of Struthers and ablation of the supracondylar process. The brachial artery can also be compressed by an anomalous insertion of the pronator teres muscle into the supracondylar process (Talha et al. 1987). 

As a rule, an accurate and systematic US examination of the dorsal muscles of the forearm should begin at the level of the wrist, where their individual tendons are easily distinguished within the six compartments. Then, US scanning should be performed by shifting the transducer upward to depict the myotendinous junction and the belly of the appropriate muscle to be evaluated. This retrograde technique is particularly helpful, even for the experienced examiner, to increase confidence on establishing the identity of the forearm muscles. At the middle third of the dorsal forearm, the muscle bellies of the superficial and deep layers are divided by a transverse hyperechoic septum (Fig. 9.9). More deeply, the hyperechoic straight appearance of the interosseous membrane and the profile of the radial and ulnar shafts separate the dorsal compartment from the volar compartment (Fig. 9.9). 

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