Evaluation of muscle fatigue using infrared thermal imaging technique with assisted electromyography

Abstract

Muscle fatigue in sports science is an established research area where various techniques and types of muscles have been studied in order to understand the fatigue condition. It can be used as an indicator for predicting muscle injury and other muscle problems which can decrease athletes’ performance. Muscle fatigue usually occurs after a long lasting or repeated muscular activity. Electromyography (EMG) assessment method is a standard tool used to evaluate muscle fatigue based on the signals from the neuromuscular activation during fatigue condition. However, additional time for equipment set up such as placement of the electrodes and the use of multiple wires make this overall setting a bit complicated. In addition, the signal from EMG which possessed some noise, need to be filtered and post processing time is also required to obtain a reliable measurement signal. Therefore, researchers have explored the application of thermal imaging technique as one of the alternative methods for muscle fatigue assessment. The objective of this study is to investigate the correlation of muscle fatigue condition measured using a non-invasive infrared thermal imaging technique and a standard evaluation method, EMG. Five healthy men were selected to run on a treadmill for 30 minutes with a constant speed setting. Temperature and EMG signals were registered from gastrocnemius muscle of the subjects' dominant leg simultaneously. Result obtained shows that the average temperature of gastrocnemius muscle decrease as subjects start to exercise. Further temperature decrease along with exercise and increase in temperature were observed during the recovery period. Statistical analysis was performed and analyzed using both temperature and EMG parameters. Result shows a significant strong correlation with r = 0.7707 and p < 0.05 between temperature difference and median frequency (MDF) for all subjects compared to average temperature. Therefore, it is concluded that temperature difference extracted from thermal images can be used as an ideal parameter for muscle fatigue evaluation.

Could Thermal Imaging Supplement Surface Electromyography Measurements for Skeletal Muscles?

“…In the case of vastus lateralis, an inverse relationship between skin temperature and sEMG was found, but in the case of BF and GM, no changes in temperature after the test were reported. However, these conclusions contrast with the result published in the next two cited studies [14], [42]. In [14], contractions of the upper limb in isometric condition were considered.…”

“…Ten volunteers were tested and it was proved that for 5%, 15%, and 30% of maximum voluntary contraction (MVC), the rms and MPF parameters were correlated ( p < 0.05) with changes in skin temperature for biceps brachii. The study by Ridzuan et al [42] presented the results for the lower limb running speed of 10 km/h and the period of 30 min. However, the experiment was carried out for only five participants.…”

“…In the case where the experiment is carried out under controlled conditions, the thermal results can be considered as significant [36], [46]. For more energetic exercises, the results can be found in works [38], [42], and [43]. It should also be emphasized that the tests were carried out using a motorized treadmill, which affects the gait parameters [47], that may have an influence on the way of firing and activation of lower limb muscles and the stabilization method.…”

Acute outcomes of acupuncture and dry needling over peripheral acute fatigue in untrained healthy volunteers: A randomized controlled clinical trial

“…Muscle contraction raises skin temperature due to increased blood flow, muscle tear, and inflammation secondary to a metabolic response proportional to the exercise, generating heat loss to the environment via convection and evaporation [ 54 ] permitting thermographic imaging to assess skin temperature. Therefore, skin temperature is related to muscle effort [ 55 ] as well as to muscle fatigue [ 17 ], indicating that a biceps brachii effort of an isometric exercise is going to generate peripheral fatigue with an alteration of skin temperature. Our study demonstrates the capability of a protocol [ 46 ] to generate peripheral muscle fatigue according to electromyographic, thermographic, and fatigue perception, according to Wolfe [ 56 ] and Kakuda et al [ 38 ], it is possible to use VAS as an instrument for the perceived subject assessment of PAF.…”

“…Over the past decade, several acupuncture studies emerged to elucidate its effects on an occidental optic [ 5 , [10] , [11] , [12] ]. Traditional Chinese acupuncture (TCA) uses needles inserted in specifics points (acupoints) through 14 main meridians in the human body [ 13 ] used frequently to treat many human conditions including chronic and acute pain [ 12 ], hypertension [ 11 ], Parkinson's [ 14 ], and fatigue itself, both peripheral [ 15 ] and chronic [ 10 ] occurring through excitatory and inhibitory effects in the motor system and improve function [ 16 ] along with vasoactive effects of TCA in the human body have also been studied regarding reverberations over skin temperature [ 5 , 17 ]. However, we are yet to understand how TCA might affect immediate muscle recovery after induced peripheral fatigue.…”