RESUMEN
Introduction: The nature of firefighters' work is characterized by its unexpected emergencies, sleep deprivation, night shift schedules, and smoke exposure during firefighting. Methods: Eighteen firefighters were involved in simulated live-fire activities. Firefighters' health status in terms of cardiovascular and mental conditions was checked by a physician and through reviewing their medical records. Firefighters' cognitive functions were evaluated by visual and auditory continuous performance tests (VCPT and ACPT) and paced visual and auditory serial addition tests (PVSAT and PASAT). Results: VCPT and ACPT scores were lower after the activity relative to baseline. The results revealed that ACPT appears to be more difficult than VCPT. Also, PVSAT and PASAT scores decreased significantly after the experiment. PASAT scores following firefighting tasks experienced a more significant decline compared to those of the PVSAT. Conclusions: These findings suggest that firefighters have visual and auditory cognitive function problems following firefighting activities. In conclusion, auditory cognitive function was more influenced than the visual ability as a result of the experiment.
Asunto(s)
Bomberos , Cognición , Humanos , Privación de Sueño/epidemiologíaRESUMEN
This study examined the impact of various types of firefighting activities on firefighters' physiological responses and cognitive function. Each firefighter was engaged in three conditions: (1) Live-fire activities (LFA), (2) Typical firefighting activities (TFA), and (3) Rescue operations at height (ROH). The effects of various types of firefighting activities on the physiological responses and cognitive function were evaluated by heart rate (HR), temporal artery temperature (TT), and the correct response (CR) on a cognitive test. The results indicated that, compared to the baseline, physiological response increased, while information processing performance decreased after the activity. Furthermore, HR and TT were significantly lower at the end of the firefighting activity in the LFA (149.33 bpm; 38.08 °C) compared with the TFA (152.22 bpm; 38.17 °C) and ROH (159.28 bpm; 38.24 °C) conditions. Also, CR was significantly higher at the end of the activity in the LFA and TFA compared with the ROH condition. The results showed that rescue at height was more intensive than the other firefighting tasks in decreasing physiological and cognitive function capacity after the experiment. Practitioner Summary: We assumed that various types of firefighting activities would have different effects on physiological and cognitive functions during firefighting activities. The Findings suggest that rescue at height operations, performed without the use of special protective equipment, was more influential than other firefighting duties in changing firefighters' physiological and cognitive capacity. Abbreviations: CR: correct response; LFA: live-fire activities; TFA: typical firefighting activities; ROH: rescue operations at height; HR: heart rate; TT: temporal artery tempearture; PASAT: pased auditory serila addition teat; FPC: firefighting protective clothing.
Asunto(s)
Cognición , Bomberos , Esfuerzo Físico/fisiología , Adulto , Análisis de Varianza , Temperatura Corporal/fisiología , Bomberos/psicología , Frecuencia Cardíaca/fisiología , Humanos , Trabajo de Rescate , Análisis y Desempeño de TareasRESUMEN
INTRODUCTION: Considering the importance of evaluating working postures, many techniques and tools have been developed to identify and eliminate awkward postures and prevent musculoskeletal disorders (MSDs). The introduction of the Microsoft Kinect sensor, which is a low-cost, easy to set up and markerless motion capture system, offers promising possibilities for postural studies. OBJECTIVES: Considering the Kinect's special ability in head-pose and facial-expression tracking and complexity of cervical spine movements, this study aimed to assess concurrent validity of the Microsoft Kinect against an electrogoniometer for neck angle measurements. METHODS: A special software program was developed to calculate the neck angle based on Kinect skeleton tracking data. Neck angles were measured simultaneously by electrogoniometer and the developed software program in 10 volunteers. The results were recorded in degrees and the time required for each method was also measured. RESULTS: The Kinect's ability to identify body joints was reliable and precise. There was moderate to excellent agreement between the Kinect-based method and the electrogoniometer (paired-sample t test, p ≥ 0.25; intraclass correlation for test-retest reliability, ≥0.75). CONCLUSION: Kinect-based measurement was much faster and required less equipment, but accurate measurement with Microsoft Kinect was only possible if the participant was in its field of view.
Asunto(s)
Imagenología Tridimensional/métodos , Cuello/anatomía & histología , Postura , Adulto , Humanos , Movimiento , Rango del Movimiento Articular , Reproducibilidad de los Resultados , Programas Informáticos , Juegos de VideoRESUMEN
OBJECTIVES: Work-related musculoskeletal disorders in the neck and shoulder regions are common among carpet weavers. Working for prolonged hours in a static and awkward posture could result in an increased muscle activity and may lead to musculoskeletal disorders. Ergonomic workstation improvements can reduce muscle fatigue and the risk of musculoskeletal disorders. MATERIAL AND METHODS: The aim of this study is to assess and to compare upper trapezius and middle deltoid muscle activity in 2 traditional and improved design carpet weaving workstations. These 2 workstations were simulated in a laboratory and 12 women carpet weavers worked for 3 h. Electromyography (EMG) signals were recorded during work in bilateral upper trapezius and bilateral middle deltoid. The root mean square (RMS) and median frequency (MF) values were calculated and used to assess muscle load and fatigue. Repeated measure ANOVA was performed to assess the effect of independent variables on muscular activity and fatigue. The participants were asked to report shoulder region fatigue on the Borg's Category-Ratio scale (Borg CR-10). RESULTS: Root mean square values in workstation A are significantly higher than in workstation B. Furthermore, EMG amplitude was higher in bilateral trapezius than in bilateral deltoid. However, muscle fatigue was not observed in any of the workstations. CONCLUSIONS: The results of the study revealed that muscle load in a traditional workstation was high, but fatigue was not observed. Further studies investigating other muscles involved in carpet weaving tasks are recommended.
Asunto(s)
Fatiga/prevención & control , Pisos y Cubiertas de Piso/normas , Fatiga Muscular/fisiología , Músculo Esquelético/fisiopatología , Enfermedades Profesionales/prevención & control , Postura/fisiología , Industria Textil , Adulto , Electromiografía , Fatiga/fisiopatología , Femenino , Humanos , Enfermedades Profesionales/fisiopatologíaRESUMEN
PURPOSE: The present study was an attempt to investigate the effect of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing. METHODS: Ten healthy subjects were recruited to stand for 2 h in three footwear conditions: barefoot, flat-bottomed shoe and unstable shoe. During standing, lower leg discomfort and EMG activity of medial gastrocnemius (MG) and tibialis anterior (TA) muscles were continuously monitored. Changes in lower leg volume over standing time also were measured. RESULTS: Lower leg discomfort rating reduced significantly while subjects standing on unstable shoe compared to the flat-bottomed shoe and barefoot condition. For lower leg volume, less changes also were observed with unstable shoe. The activity level and variation of right MG muscle was greater with unstable shoe compared to the other footwear conditions; however regarding the left MG muscle, significant difference was found between unstable shoe and flat-bottomed shoe only for activity level. Furthermore no significant differences were observed for the activity level and variation of TA muscles (right/left) among all footwear conditions. CONCLUSIONS: The findings suggested that prolonged standing with unstable footwear produces changes in lower leg muscles activity and leads to less volume changes. Perceived discomfort also was lower for this type of footwear and this might mean that unstable footwear can be used as ergonomic solution for employees whose work requires prolonged standing.
Asunto(s)
Pierna/fisiología , Músculo Esquelético/fisiología , Zapatos , Adulto , Electromiografía , Humanos , Imagen por Resonancia Magnética , Masculino , Dolor Musculoesquelético/etiología , Postura , Factores de Tiempo , Adulto JovenRESUMEN
OBJECTIVES: Increasing bilateral gluteus medius co-activation has been identified as one of the most important factors in developing low back pain due to prolonged standing in healthy people. This study aims to investigate the impact of an anti-fatigue mat on the bilateral gluteus medius co-activation pattern and to report the low back pain subjectively in 2 different standing positions on the normal rigid surface and on the anti-fatigue mat. MATERIAL AND METHODS: While carrying out an easy simulated profession, 16 participants who had no low back pain background were requested to stand for 2 h in each position, with and without using the anti-fatigue floor mat, respectively. At the beginning of standing process and at every 15 min until the time of 120 min lapses, electric activities for the bilateral gluteus medius co-activation and subjective pain level in low back area were collected by the surface electromyogeraphy (EMG) and the visual analogue scale (VAS), respectively in each position. RESULTS: The obtained findings revealed that the anti-fatigue mat significantly decreased subjective pain level in low back area among 15 participants (p < 0.05). However, there was objectively no significant difference in the bilateral gluteus medius co-activation pattern among the participants between the position 1 and the position 2 (p > 0.05). The findings obtained under this study related to the impact of the anti-fatigue mat upon the low back pain based on the increase of > 10 mm on the VAS threshold, which showed that this intervention had no significant impact upon decreasing the number of patients suffering from the low back pain and also minimizing the bilateral gluteus medius co-activation in both pain developer groups (p > 0.05). However, 73% of the participants preferred to apply it. CONCLUSIONS: It seems that the anti-fatigue mat may be useful in reducing the low back pain although it objectively didn't significantly change the gluteus medius co-activation pattern related to the low back pain.
Asunto(s)
Pisos y Cubiertas de Piso , Dolor de la Región Lumbar/prevención & control , Dolor de la Región Lumbar/fisiopatología , Músculo Esquelético/fisiopatología , Salud Laboral , Nalgas , Estudios Cruzados , Método Doble Ciego , Electromiografía , Humanos , Masculino , Dimensión del Dolor , Postura , Adulto JovenRESUMEN
Introduction. The majority of industrial accidents occur because of human errors. Human error has different causes, however, in all cases cognitive abilities and limitations of human play an important role. Occupational cognitive failures are cognitively-based human errors that occur at work. The aim of this study was to examine the relationship between occupational cognitive failures and safety consequences. Method. Personnel of a large industrial company in Iran filled out an occupational cognitive failure questionnaire (OCFQ) and answered questions on accidents. Univariate and multiple logistic regression analysis were used to determine the relationship between cognitive failures and safety consequences. Results. According to developed regression models, personnel with a high rate of cognitive failure, in comparison to low rate, have a high risk of minor injury involvement (OR 5.1, 95% CI [2.62, 10.3]); similar results were for major injury and near miss. Discussion. The results of this study revealed usefulness of the OCFQ as a tool of predicting safety- related consequences and planning preventive actions.
Asunto(s)
Accidentes de Trabajo/psicología , Accidentes de Trabajo/estadística & datos numéricos , Cognición , Traumatismos Ocupacionales/epidemiología , Traumatismos Ocupacionales/psicología , Lugar de Trabajo/estadística & datos numéricos , Adulto , Humanos , Industrias/estadística & datos numéricos , Irán , Masculino , Persona de Mediana Edad , Factores SocioeconómicosRESUMEN
INTRODUCTION: The impact of a driver's cognitive capability on traffic safety has not been adequately studied. This study examined the relationship between cognitive failures, driving errors and accident data. METHOD: Professional drivers from Iran (160 males, ages 18-65) participated in this study. The cognitive failures questionnaire (CFQ) and the driver error questionnaire were administered. The participants were also asked other questions about personal driving information. A principal component analysis with varimax rotation was performed to determine the factor structure of the CFQ. Poisson regression models were developed to predict driving errors and accidents from total CFQ scores and the extracted factors. RESULTS: Total CFQ scores were associated with driving error rates, but not with accidents. However, the 2 extracted factors suggested an increased effect on accidents and were strongly associated with driving errors. DISCUSSION: Although the CFQ was not able to predict driving accidents, it could be used to identify drivers susceptible to driving errors. Further development of a driving-oriented cognitive failure scale is recommended to help identify error prone drivers. Such a scale may be beneficial to licensing authorities or for developing driver selection and training procedures for organizations.