Exercise and Health Education for Textile Workers: A Pre-Post Study

Change in the score on the Numerical Rating Scale (NRS). The NRS scale for pain assessment is a scale that measures the intensity of pain experienced by the patient. It is a numerical rating scale where the patient is asked to rate their pain between 0 and 10. The reported values are classified as follows: no pain = 0; mild pain = 1,2; moderate pain = 3-5; severe pain = 6-8; unbearable pain = 9-10.

Musculoskeletal disorders will be evaluated using the Standardized Nordic Musculoskeletal Questionnaire (Kuorinka), a self-administered questionnaire consisting of 11 multiple-choice items. The questionnaire provides information on the presence of pain, fatigue, or discomfort in different musculoskeletal body regions. It is designed to detect early musculoskeletal symptoms and to support the analysis of potential ergonomic risk factors. Higher values indicate a greater burden of musculoskeletal symptoms.

Upper limb muscle strength will be assessed using the handgrip strength test, measured with a hand-held dynamometer (Takei Grip-D). Participants will be seated on a chair with the elbow flexed at 90 degrees and the forearm in a neutral position. Participants will perform a maximal handgrip contraction for up to 3 seconds. Three trials will be conducted, with a 1-minute rest period between attempts. Handgrip strength will be recorded in kilograms (kg), with higher values indicating greater upper limb muscle strength.

Lower limb muscle strength will be measured using the 30-second Sit-to-Stand-Test (STST).Participants will begin seated on a chair with feet slightly apart and flat on the floor, and arms crossed over the chest. Upon a verbal signal, participants will rise to a full standing position and return to the seated position as many times as possible within 30 seconds. Only correctly completed repetitions, as well as repetitions reaching more than half of the full range of motion at the end of the test, will be counted. Higher numbers of repetitions indicate greater lower limb muscle strength.

Physical Activity level will be assessed using the International Physical Activity Questionnaire, Short Form (IPAQ-SF), a validated self-administered questionnaire consisting of 7 items. The questionnaire records the frequency (days per week) and duration (hours and minutes per day) of physical activity performed during a reference week. It is a standardized instrument widely used internationally for population-based physical activity assessment. Higher scores indicate higher levels of physical activity.

Work ability will be measured with the Work Ability Index (WAI). The WAI is a self-reporter questionnaire based on the worker's self-perception of their capacity to perform work tasks in relation to job demands and current health status. It includes eleven questions grouped into seven dimensions and generates an overall score reflecting current work ability, as well as an estimation of work ability over the following two years. Higher scores represent better perceived work ability.

Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), a 19-item self-administered questionnaire measuring multiple aspects of sleep, including sleep quality, latency, duration, efficiency, disturbances, and daytime dysfunction. Each item is scored to contribute to a global score ranging from 0 to 21, where 0 indicates no sleep difficulties and 21 indicates severe sleep problems. Higher scores reflect poorer sleep quality.

Depression, anxiety and stress will be measured with the Depression, Anxiety and Stress Scale (DASS-21). In this scale, each item is answered according to the intensity of each symptom suffered in the last week on a Likert scale from 0 to 3 points. The global scale contains three different blocks for: depression, anxiety and stress. Each block has seven items. The global scale score ranges from 0 to 21 points. In the Depression, Anxiety and Stress Scale, higher scores indicate higher levels of stress, depression and anxiety.

Change in health-related quality of life will be assessed using the EuroQol 5-Dimension 3-Level questionnaire (EQ-5D-3L), Spanish version. The EQ-5D-3L is a validated instrument that can be self-administered or administered via interview to assess health-related quality of life across multiple dimensions, including mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The questionnaire comprises five items, each with three response levels (no problems = 1, some problems = 2, extreme problems = 3). Responses are coded and weighted to generate an index value. Additionally, the EQ-5D-3L includes a 20-centimeter vertical visual analogue scale (VAS) ranging from 0 (worst imaginable health state) to 100 (best imaginable health state), on which participants rate their current perceived health status. Higher scores indicate better health-related quality of life.

Work absenteeism will be evaluated using the Work Productivity and Activity Impairment Questionnaire (WPAI), a validated self-administered instrument that measures the impact of health problems on work productivity. The absenteeism domain assesses the percentage of work time missed due to health-related reasons during the previous 7 days. Higher percentages indicate greater work absenteeism.