A field experiment comparing mechanical demands of two pruners for flower cutting

Abstract

Manual flower cutting requires repetitive forceful movements that may explain the high incidence of upperextremity MSDs among workers of the Colombian flower industry. Force demands may be caused by the use of pruners that have not been designed for Colombian workers. We conducted a repeated measures field experimental study (n=16, 69% women, 20 to 60 years old) to compare the mechanical demands during rose cutting of two different pruners (Traditional vs. alternative pruner) at two different cutting heights (elbow vs. over-shoulder). Demands included the perceived comfort, perceived effort and upper limb´s muscular activity and posture. Workers perceived their traditional pruner as more comfortable but requiring more effort than the prototype tool. No benefits were observed regarding ulnar deviation with the alternative pruner. The wrist extension and related muscular activity of the wrist extensors were higher with the prototype pruner. The prototype pruner resulted in reduced muscular load of the wrist flexors; the biceps when working at the elbow height; and the deltoids when working at the shoulder height. However, Moderate results may be explained by the lack of time for workers' adaptation to the alternative tool. New design developments must focus on reducing extension and ulnar deviation of the wrist.

Assessment of Muscular Activity and Postural Load During Coffee Harvesting Activities – A Case Study

“…Surface electromyography signals recorded in ASCII were processed using algorithms developed in MATLAB R 2013a (USA). The RMS signal (root mean square) was estimated from a moving window of 200 ms [8] and normalized with each muscle's MVC (Maximum Voluntary Contraction) record. P10 (static level), P50 (medium level) and P90 (dynamic level) were estimated using the amplitude probability distribution function (APDF).…”

“…A postural and muscular analysis was applied using electrogoniometry (EGM) and electromyography (EMG), while the worker performed the activity for 20 minutes. A video recording was made to analyze three specific postures: arms up, arms in a neutral position and arms down [8], [12].…”

Análisis biomecánico en la actividad de recolección café en Colombia

“…Also, an informed consent was shared and read to them, and they voluntarily participated in the measurement. [12,8]. Source: authors.…”

“…The researches fields regarding worker conditions have been investigated only in floriculture and coffee. In the floricultural activity, the research made an evaluation where it was carried out taking Nordic questionnaires, evaluation by video, and direct measurements in terms of postures and muscle activity (electromyography (EMG) and electro goniometry (EGM)), design of a prototype cutting tool and its evaluation in real conditions [7,8,9,10]. Otherwise in the coffee activity what was done refers to improvements in crop mechanization and the different tools to help to increase the crop harvesting activity [11].…”

Análisis de la disminución de fuerza de agarre en la mano por uso de guante en actividades de aseo y cafetería

“…En Colombia existen algunos estudios que evalúan las LME en poblaciones particulares, por ejemplo, trabajadores administrativos en universidades, personas que laboran en una administradora de riesgos profesionales, en extracción minera, en una caja de compensación, en el sector floricultor y en la industria de alimentos, entre otros (15)(16)(17)(18)(19)(20)(21)(22)(23).…”