Background Upper extremity musculoskeletal disorders negatively affect ability to perform activities of daily living, self-care and work. Therefore, outcome measurements that address muscle strength, fatigue resistance, functionality and work physical capacity must be defined to assess and plan specific actions to minimize them. Objective To investigate the association of upper extremity muscle strength with upper extremity fatigue resistance, work ability and upper extremity dysfunction in a sample of workers from a tertiary hospital. Methods Shoulder and elbow isokinetic strength were assessed by Biodex System 4™, isometric hand grip by JAMAR™, upper extremity fatigue resistance by Functional Impairment Test Hand and Neck/Shoulder/Arm (FIT-HaNSA), ability to work by the Work Ability Index and upper extremity dysfunction by the Quick-Disabilities of the Arm, Shoulder and Hand QuickDASH-Br questionnaire. The Nordic questionnaire and Numeric Pain Rating Scale (NPRS) were used for pain description. The associations were analysed by Spearman’s correlation coefficient (rho) (p < 0.05). Results Twenty-seven participants: 59.2% women; mean age 46 years old; 70.3% obese/overweight; 62.9% active with predominantly dynamic muscle contraction work. Besides predominance of good to moderate work ability (81.4%) and comorbidities (37%), all participants had symptoms of the upper extremities for at least 12 months, with a predominance of low-intensity in the shoulder (55.5%). In addition, 88.8% reported pain in other segments. Muscle strength of abduction (rho = 0.49), adduction (rho = 0.40), internal rotation (rho = 0.44) and hand grip (rho = 0.68) presented moderate correlation with FIT-HaNSA. Hand grip (rho = − 0.52) showed moderate correlation with upper extremity dysfunction. Conclusions The results of this preliminary study suggested the association of shoulder strength with fatigue resistance. Also, hand grip strength was associated with upper extremity dysfunction and fatigue resistance. No association was found with the Work Ability Index in this sample. So, it is suggested that hand grip and shoulder strength could be outcome measurements used for future interventions focused on upper extremity preventive exercises to improve strength and fatigue resistance of workers at risk for the development of musculoskeletal disorders. Other individual, psychosocial and organizational risk factors must also be considered as influences on upper extremity function.

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IntroductionThe upper extremity is related to the functional ability to perform activities of daily living, self-care and work. Complaints in the upper limbs negatively affect these skills, therefore, it is necessary to obtain information about work demands.ObjectiveTo correlate upper limb muscle strength with fatigue resistance, work ability and dysfunction in a sample of workers from a university hospital.MethodsShoulder and elbow strength were assessed by Biodex System 4™, hand grip by JAMAR™, fatigue resistance by Functional Impairment test Hand/Neck/Shoulder/Arm (FIT-HaNSA), the ability to work by the Work Ability Index and upper limb dysfunction by QUICK-DASH-Br. The Brazilian version of the Pain Catastrophising Scale (B-PCS) was applied in order to analyse the catastrophic profile of the sample. The correlations were analysed by Spearman's Correlation Coefficient (rho)(p < 0.05).Results27 workers presented with chronic pain of low intensity, were classified as active and underwent predominantly dynamic work. Muscle strength of abduction (0.49), adduction (0.40), internal rotation (0.44), elbow flexion (0.38) and hand grip (0.68) had a direct correlation with FIT-HaNSA. Only hand grip (-0.52) showed an inverse correlation with upper limb dysfunction. Muscle strength was not correlated with work ability or pain catastrophising.ConclusionThe results suggested that increasing muscle strength may improve fatigue resistance. Also, improving hand grip strength could decrease upper limb dysfunction. In contrast to previous findings, muscle strength was not related to the ability to work or to pain catastrophising, because these factors are not only influenced by physical function, but also by psychosocial functioning.