Application of Near-Infrared Spectroscopy methods to functional and patophysiological alterations of skeletal muscle

<p>A project focused in new applications of NIRS technique for monitoring skeletal muscle conditions in sports and occupational medicine</p

Determination of the utility of near-infrared spectroscopy in the study of exertional myalgia and chronic exertional compartment syndrome in musicians’ forearms

<p>The non-invasive and real-time near-infrared spectrometry (NIRS) has been proven to distinguish<br>between individuals with chronic exertional compartment syndrome (CECS) and healthy individuals based on a significantly lower tissue oxygenation index (TOI) or tissue saturation index (TSI), during exercise provocation. The use of abnormal Intracompartmental pressure values remain as the most solid method to diagnose individuals as CECS. However, supposedly healthy individuals with CECS-like criteria in terms of abnormal ICP values are harder to distinguish and require further looking into each patient's medical history. In addition, as the nature of the method is quite prone to cause discomfort in subjects and is not risk-free, an alternative methodology that causes less discomfort and is less time consuming may be preferable. Our results reinforce the real-time NIRS measurement as being a fair non-invasive replacement for direct ICP measure to detect CECS indirectly, focusing on the TOI trace.</p

The dynamics of skeletal muscle oxygen extraction during exercise at simulated altitude

<p>NIRS measurements are a suitable way to study<br>the muscle's oxygenation profile during exercise<br>and acute exposure to high altitude in a hypoxic<br>chamber. At 5000 m, the range of variation of muscle<br>oxygen extraction (during the entire exercise<br>protocol) was about 50% less compared to sea level<br>measurements. The fact that the total peripheral resistance reaches a plateau whilst the local oxygen extraction increases more readily, indicates that the main limiting factor for oxygen delivery in active muscle at high altitude is the low oxygen saturation in arterial blood  rather than local capacity for vasodilation.</p

Transcutaneous oxymetry determined with near-infrared spectroscopy of the anterior compartment of the leg in patients with chronic exertional compartment syndrome

<p>We describe the usefulness of NIRS technology in order to the non-invasive diagnosis of chronic exertional compartment syndrome (CECS).</p

Normalised method to quantify the oxygenation profile of skeletal muscle with real time NIRS measurement

<p>The main technical limitation of the real time NIRS in vivo measurement is the difficulty in obtaining a calibrated scale for quantification purposes, because a zero setting is impossible to reach under physiological conditions. A lower arm exercise during the occlusion allows the lowest O2-Hb level to be reached as quickly as possible without causing<br>excessive discomfort due to the pressure exertion. Once the plateau is evident the exerted pressure is relieved. Although this is a rough estimate of the absolute concentration levels of O Hb and HHb, it still gives us a more accurate description of the dynamic changes of the oxygen supply at tissular level. The ischemic arrest is not a new method to evaluate the lowest O2-Hb concentration, but in order to map the oxygenation profile in a detailed way; we propose some alterations to this technique.</p> <p> </p

Effect of intermittent hypobaric hypoxia on induced muscle injury repair in laboratory rats (DEP2010-22205-C02-01)

<p>A study aimed to establish the possible efficiency of intermittent hypobaric hypoxia exposure in the recovery of induced muscle damage in rats.</p

Structural and biochemical evidences for the effect of exercise and intermittent hypobaric hypoxia on the recovery from eccentric exercise-induced muscle damage in trained rats

<p>In rat soleus muscle, a recuperation programme of IHH combined with light exercise seems to induce a faster<br>recovery of the mean muscle fibres size and a significant decrease in the percentage of abnormal fibres, without affecting neither the percentage of fibre types nor the fibre shape.</p

Plasma myoglobin and creatine kinase after skeletal muscle injury in trained rats: The effect of intermittent hypobaric hypoxia and light exercise.

<p>ELISA tests on plasma were used as a rapid method to determine the existence of muscle damage in trained rats. Myoglobin in plasma showed a different dynamics in the active recovery group, perhaps indicating a different degree of injury in the<br>oxidative fibres. However, the CK level might not be the best representative parameter to accurately evaluate the actual level of the muscle damage produced.</p

Profiling with near-infrared spectroscopy of the forearm’s extensor digitorum during intermittent muscle fatigue protocol with motorcycle riders and control group

<p>An intermittent protocol of cyclic breaking bouts at distinct submaximal intensity of the maximal voluntary contraction does not reflect any significant changes in order to differentiate between the control group and the group of the professional motorcyclist, in terms of the TSI% value, or the other traces, separately. We feel that several trial and error measurements for developmental purposes, will eventually give us a good map for oxygenation profiling as it is not yet explored to its potential advantages.</p

Intermittent hypobaric hypoxia and light aerobic exercise increase circulating haematopoietic stem cells in rats during skeletal muscle damage recovery

<p>Intermittent hypobaric hypoxia and light aerobic exercise could be beneficial for a skeletal muscle damage recovery. Rats combining hypoxic exposure and light runing for 15 minutes showed a higher increase of haematopoietic stem cells in<br>the peripheral blood after muscle damage.</p