Skripsi a.n SHAYNA PUTRI SULHAH (F1401221014)

Abstract

Pemanenan kelapa sawit di Indonesia masih dilakukan secara manual menggunakan egrek, sehingga membuat pemanen rentan mengalami musculoskeletal disorders (MSDs) akibat postur kerja tidak ergonomis dan kontraksi otot berulang, terutama pada aktivitas cutting. Upper Limb Exoskeleton (ULE) passive dikembangkan oleh IPB University bersama Badan Riset dan Inovasi Nasional (BRIN) sebagai alat bantu untuk mengurangi beban kerja otot pemanen. Penelitian ini bertujuan mengetahui tingkat aktivasi otot biseps, deltoid, trapezius, dan lumbar pada sisi kanan dan kiri tubuh pemanen selama aktivitas cutting, serta mengevaluasi pengaruh penggunaan ULE terhadap aktivasi otot tersebut. Data direkam menggunakan sensor surface electromyography (sEMG) Delsys Trigno pada delapan titik otot dari empat subjek pemanen aktif, dinormalisasi menjadi percent Maximum Voluntary Electrical Activation (%MVE), lalu dibandingkan antara kondisi tanpa ULE (Non-ULE) dan dengan ULE menggunakan paired t-test serta effect size Hedges' g. Hasil uji statistik menunjukkan tidak terdapat perbedaan aktivasi otot yang signifikan antara kondisi Non-ULE dan ULE pada seluruh otot yang diamati (p>0,05), dengan effect size tertinggi pada trapezius kiri (Hedges' g=0,65; kategori sedang). Secara deskriptif, penggunaan ULE menurunkan aktivasi otot pada sisi kanan tubuh, seperti deltoid kanan (turun 25,72%) dan trapezius kanan (turun 14,77%), namun justru meningkatkan aktivasi pada sisi kiri, seperti biseps kiri (naik 24,05%) dan trapezius kiri (naik 21,78%). Temuan ini mengindikasikan bahwa penggunaan ULE belum menurunkan beban kerja otot secara merata dan signifikan secara statistik, melainkan lebih berpotensi mendistribusikan ulang beban kerja dari sisi kanan ke sisi kiri tubuh pemanen.

Oil palm harvesting in Indonesia is still carried out manually using a sickle pole (egrek), making harvesters prone to musculoskeletal disorders (MSDs) due to non-ergonomic working postures and repetitive muscle contractions, particularly during the cutting activity. A passive Upper Limb Exoskeleton (ULE) was developed by IPB University in collaboration with the National Research and Innovation Agency (BRIN) as an assistive device to reduce harvesters' muscle workload. This study aimed to determine the activation level of the biceps, deltoid, trapezius, and lumbar muscles on the right and left sides of harvesters' bodies during cutting activity, and to evaluate the effect of ULE use on that muscle activation. Data were recorded using Delsys Trigno surface electromyography (sEMG) sensors at eight muscle sites from four active harvester subjects, normalized into percent Maximum Voluntary Electrical Activation (%MVE), and compared between conditions without ULE (Non-ULE) and with ULE using paired t-tests and Hedges' g effect size. Statistical results showed no significant difference in muscle activation between the Non-ULE and ULE conditions across all observed muscles (p>0.05), with the highest effect size found in the left trapezius (Hedges' g=0.65; medium category). Descriptively, ULE use decreased muscle activation on the right side of the body, such as the right deltoid (decreased by 25,72%) and right trapezius (decreased by 14,77%), but increased activation on the left side, such as the left biceps (increased by 24,05%) and left trapezius (increased by 21,78%). These findings indicate that ULE use has not yet reduced muscle workload evenly and significantly but rather tends to redistribute the workload from the right to the left side of the harvester's body.