Ergonomic evaluation of standard and alternative pallet jack handless

摘要: Abstract Aim Transportation of materials using a pallet jack pulled behind the operator is common due to visual advantages while transporting fully loaded pallets. The objective this laboratory study was quantify muscle activity, posture, and low back compressive shear forces completing typical activities standard handle that required one handed pulling compared an alternative allowed for two pushing. Methods Participants (n = 14) performed six ten trials tasks (straight travel turning) with each handle. Posture analysis trunk right upper extremity Motion Analysis (Santa Rosa, CA, USA) were analyzed 3D Static Strength Prediction Program (University Michigan, Ann Arbor, MI). Activity trapezius (UT), pectoralis major (PM), flexor digitorum superficialis (FDS) extensor (ED) muscles recorded (Telemyo 2400 T, Noraxon, Scottsdale, Arizona) normalized percent reference voluntary contraction values. All outcomes paired t-test. Results Peak mean activity PM (p  Discussion outperformed regard activity. had significantly greater at L5/S1 pushing nature hand-handle interface, yet increased both L4/L5 levels in back. Conclusion In analysis, there not clear benefit either terms strength capacity varied benefits drawbacks when comparing However, given favorable subjective reports described prior publication, reliance on dynamic versus passive force production, facilitating workers' ability push travelling large loads worth further investigation.