Is Repetitive Workload a Risk Factor for Upper Extremity Musculoskeletal Disorders in Surgical Device Mechanics? A Cross-Sectional Analysis

Abstract

To assess the prevalence of upper extremity work-related musculoskeletal disorders (WMSDs) among surgical device mechanics compared to a control group, a total of 70 employees were included and assigned to three occupational groups (grinders, packers, and control). Personal factors, work exposure, manual skill, and complaints were assessed by two self-administered questionnaires and an industry test. WMSDs were diagnosed in a standardised clinical examination. The two-one-sided t-tests (TOST) procedure was used to test the clinical equivalence of the respective grinding and packaging groups vs. the control group in terms of the Disabilities of the Arm, Shoulder and Hand (DASH) score. Thirty-nine study participants (56%) experienced at least one WMSD at the elbow, forearm, and/or wrist, mainly with signs of epicondylitis and nerve entrapment at the medial elbow. The risk of grinders developing upper extremity WMSD was about 2.5-times higher and packers had an 8.6-fold higher risk of a clinically relevant DASH > 29 compared to the control group. However, these differences were not statistically significant. The groups were also proven to be clinically equivalent in terms of DASH score. Surgical device mechanics do not seem to have worse DASH values or be at higher risk of upper limb WMSDs compared to a control group. This is the first study to analyse and compare different workplaces in this industry that are also common in other industries.

Predictors for Outcomes related to upper Extremity Musculoskeletal Disorders in a healthy Working Population: a methodological Approach

“…The study was initially powered for the proof of the hypothesis of clinical equivalence of occupational groups in regard to the DASH score [17]. This hypothesis could be con rmed by primary analysis.…”

“…No incentives were offered. Eligibility criteria were applied according to our previous publication [17]. The participants were asked to ll in two standardised self-administered questionnaires.…”

“…Random samples were drawn from these groups after completion of the questionnaires and proving eligibility, so that a total of 70 subjects (grinding n = 20, packaging n = 24, control n = 26) were included in the study. The subjects were predominantly men (67% (47 For the study population owchart and detailed demographic data in the individual groups, please refer to our previous publication [17].…”

“…Furthermore, the study designs and research methods used to collect and process data via WMSDs are extremely heterogeneous. Our literature search revealed that out of 262 original research articles, only about 4% of the studies contained a clinical examination of the subjects with or without structured questionnaires / interviews including a control group [17].…”

Predictors for Clinical Outcomes Related to Upper Extremity Musculoskeletal Disorders in a Healthy Working Population

“…No incentives were offered, and participation decision was met voluntarily on invitation by signing the informed consent. The following eligibility criteria were applied according to our previous publication [17]: Age < 18 or > 65 years; employment in the respective workplace for less than 5 years; currently not on sick leave; no absence from work due to upper extremity pain for more than 2 weeks within the last 3 months; and none of the following conditions: cervical spine syndrome or herniated intervertebral disc, shoulder pain radiating into the forearm, debilitating congenital malformation of the upper extremity, rheumatoid conditions including fibromyalgia, previous upper extremity surgery due to nerve entrapment syndrome(s), and/or chronic musculoskeletal disorders, such as tennis elbow; golfer's elbow; or tenosynovitis of the flexor and/or extensor tendons, including trigger finger and de Quervain's disease, and three or less unanswered items in the DASH disability/symptom questionnaire.…”