Physiotherapeutic Training Reduces Muscle Stiffness and Fatigue in Sedentary Administrative Workers: A Biomechanical Assessment Using Myotonometry and Electromyography

Prolonged sitting is a common occupational exposure among administrative and office workers and is associated with increased postural muscle stiffness, fatigue, and musculoskeletal discomfort. This study aimed to evaluate whether a dedicated physiotherapeutic training programme can reduce biomechanical indicators of muscle overload in sedentary administrative staff. Forty-five female administrative employees were allocated to an intervention group (n = 22) or a control group (n = 23). The intervention group completed a four-week supervised physiotherapeutic programme comprising three 45 min sessions per week, including stretching, strengthening, and sensorimotor exercises targeting postural muscles. Muscle stiffness was assessed using myotonometry, while muscle fatigue was evaluated with surface electromyography based on median frequency slope analysis. The intervention effect was assessed using ANCOVA, with post-intervention values adjusted for corresponding baseline values. The intervention group showed significant reductions in muscle stiffness and fatigue, particularly in the upper trapezius and thoracic erector spinae, with moderate-to-large effect sizes. These findings indicate that targeted physiotherapeutic training can improve neuromuscular function and fatigue resistance in sedentary workers. Incorporating structured physiotherapeutic exercise into workplace health programmes may support musculoskeletal resilience and reduce the biomechanical consequences of prolonged sitting.