Evaluation of physiological cost and subjective assessment of existing coconut climbing devices

Abstract

At present there are different models of coconut climbing devices available in the market. Most of the climbing devices safety and efficiency aspects are not being studied and needs to be comparatively evaluated and modified. In this study five coconut climbing devices were selected, those are Sit and climb type (TNAU model), Standing type (Chemberi model), KAU coconut palm climber (developed at KCAET), Kerasureksha (Model developed at ARS, Mannuthy) and CPCRI model coconut climbing device. Pertinent anthropometric dimensions of human subjects with reference to the dimensions and positions of the functional components of coconut climbing devices was identified and 35 different body dimensions useful for the design or redesign of coconut climbing devices were recorded by following standard anthropometric procedure. Ten subjects (five each for men and women) were selected, conforming to statistical requirements of anthropometric dimensions. The selected ten subjects were screened for normal health through medical and bio-clinical investigations which includes Electro Cardio Graph (ECG), blood pressure and bio-clinical analysis. Selected ten subjects were calibrated in the laboratory by indirect assessment of oxygen uptake. The relationship between the heart rate and oxygen consumption of the subjects was found to be linear for all the subjects. Then energy cost of operation of the selected coconut climbing devices were computed by multiplying the oxygen consumed by the subject during the trial period with the calorific value of oxygen as 20.88 kJ lit -1 . Energy cost is comparatively less for KAU coconut palm climber with other models. Mean energy cost of male subjects during the operation of KAU coconut palm climber is 23.16 kJ min -1 and female shows 25.73 kJ min -1 . Variation of heart rate and energy cost of both male and female for selected five models were statistically analyzed. Female subjects are significantly differed in both heart rate and energy cost on different coconut climbing devices and all the female subjects showed minimum heart rate while operating KAU coconut palm climbing device. But male subjects are shown any significant difference for both heart rate and energy cost. But they shows comparatively lessheart rate for KAU coconut palm climbing device. The oxygen uptake in terms of VO 2 max was minimum for KAU coconut palm climber (58.53 per cent) while it was 65.22 per cent for Sit and climb type (TNAU model) for male operators. Similarly for female subjects, minimum for KAU coconut palm climber (74.30 per cent). Sit and climb type (TNAU model) is difficult in operation compared with other devices. Major discomfort was happened in left thigh, right thigh, left foot and right foot. Based on these results it was found that KAU coconut palm climber and Kerasuraksha coconut climbing device were identified as more suitable for climbers than other climbing devices. Seating unit of Kerasuraksha coconut climbing device and pedal unit of KAU coconut palm climber were ergonomically comfortable for the climbing operator and developed a new model by incorporating the constructional behavior of both KAU coconut palm climber and Kerasuraksha coconut climbing device. Energy expenditure of new model for male is decreased by the rate of 10.8per cent when compared to Sit and climb type (TNAU model and with KAU coconut palm climber it is comparable. In the case of female subjects, Energy cost of new model was decreased by 7.8 per cent with Kerasuraksha coconut climbing device and 6.2 per cent with Sit and climb type (TNAU model) and it is comparable with KAU coconut palm climber. Mean VO 2 , VO 2 max and work pulse of new model is 1.10, 58.16 per cent and 69.70 beats min -1 for male and for female it is 1.22, 73.45 per cent and 81.10 beats min -1 respectively. These values are comparatively less than value of other five models. The time required for climbing new model was 65.01 sec for male subjects which are less than other five selected coconut climbing devices and same trend for female also. The setting time of the new model was 65 sec while for KAU coconut palm climber it was 150 sec. compare to KAU coconut palm climber. Time was reduced by 56.67 per cent