Rosa Mª Cibrián Ortiz de Anda

Relationship between skin temperature and muscle activation during incremental cycle exercise.

While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four body regions of interest corresponding to the muscles where neuromuscular activations were monitored. Frequency band analysis was conducted to assess spectral properties of EMG signals in order to infer on priority in recruitment of motor units. Significant inverse relationship between changes in skin temperature and changes in overall neuromuscular activation for vastus lateralis was observed (r<-0.5 and p<0.04). Significant positive relationship was observed between skin temperature and low frequency components of neuromuscular activation from vastus lateralis (r>0.7 and p<0.01). Participants with larger overall activation and reduced low frequency component for vastus lateralis activation presented a better adaptive response of their thermoregulatory system by showing fewer changes in skin temperature after incremental cycling test.

Effect of bike-fit in the perception of comfort, fatigue and pain.

ABSTRACT The aim of this study was to assess the influence of different bike positions on the perception of fatigue, pain and comfort. Twenty cyclists underwent three tests that involved cycling for 45 min at their individual 50% peak aerobic power output while adopting different positions on the bike. Participants performed the cycling tests adopting three positions defined by two parameters (knee flexion angle [20°, 30°, 40°] and trunk flexion angle [35°, 45°, 55°]) in random order. Angles were measured using a 2D motion analysis system during cycling and applying Fonda’s correction factor. Perceptions of comfort, fatigue and pain were reported before the end of each test. The combination of 40° knee flexion and 35° trunk flexion was perceived as the most uncomfortable position. Moreover, greater knee flexion had a negative effect on trunk comfort, accompanied by greater levels of fatigue and pain perception in the anterior part of the thigh and knee. In conclusion, cyclists perceived the most comfortable position to be when the saddle height was within the recommended knee angle (30° calculated from the offset position or 40 ± 4.0° of absolute value). Upright trunk was found to be the most comfortable position for recreational cyclists, where aerodynamics is not so important. Cyclists’ bike perceptions should be taken into account when it comes to choosing the most beneficial position, since this can play a role in injury prevention and enhance cycling performance.

Infrared Thermography Versus Conventional Image Techniques in Pediatrics: Cases Study

The use of infrared thermography has been shown to be useful in several areas. Its applicability in medicine is based on the fact that the skin emits spontaneously and continuously infrared radiation, whose body distribution is symmetrical in a healthy individual. Infrared thermography can offer an alternative to X-rays for a large number of diseases related to peripheral vascularization. In these cases, infrared thermography can avoid the use of biologically ionizing radiation. This is of special interest in pediatric patients who, because of their age, are more radiosensitive.

Multi Regression Analysis of Skin Temperature Variation During Cycling Exercise

In the last years, infrared thermography (IRT) has become a popular technique to determine human skin temperature during exercise [1–3]. IRT presents several applications in sport science such as the detection of injury, the thermophysiology assessment, the sport clothing assessment/design, or its application in equestrian sport, among others [3]. However, IRT in sports is still a recent topic and there are many fundamental discussions concerning different methodological aspects, being one of them the analysis of the thermal data [4].

Displacement measurement in building model by speckle photography technique

Speckle photography is a powerful tool adequate to determine small displacements, in micrometer range. Through this information, other characteristics of structure deformation under loads can be determined as stress and strain distribution. In this paper we present the results obtained by applying speckle photography technique to study the behavior of building model. The displacement whole field was obtained by pointwise method. Also we present the strain distribution obtained by finite element method to compare the results obtained by these techniques.