Blog Five: Ergonomic Analysis

I will start with a definition of ergonomics.

Ergonomics is about “examining and optimising the interaction between the human worker and the non human work environment”(Jacobs & Jacobs, 2009, p. 86).

You can evaluate ergonomics by considering the POE. The Person, Occupation and Environment framework.

Person – I adore gardening and find it restful although physically challenging. I am a middle aged woman, who is not afraid of big challenges, hard work or taking on traditional male roles. I also have a long history of back pain.

Occupation – Removal of well established gorse by cutting down with chainsaw and poisoning the stump.

Environment – The activity is performed on gently sloping boundary line of our land. The gorse is over fifty years old and one and a half times my height. This gorse has substantial trunks and requires a chainsaw rather than a handsaw. Gorse is prickly to handle, and the environment is covered with debris making the work difficult. The work space is restricted and cramped. My activity demands working uncomfortably at times.

Thus with ergonomics you would consider all three elements together and conclude several points;

These include my having to  work in sustained positions where I hold the chainsaw (weight + vibration), at any height from 0-2 metres in height. My working posture involves sustained high reaches and also bending, twisted positions as I work toward the stumps.

I have to know how the weight of the foliage that will press on the bar of the chainsaw and compensate with multiple cuts or wedges. Every action needs to be analysed carefully.

There is minimal optimisation of the non human environment, as the gorse is fixed, however I do analyse the execution of the activity to the environment I work in. This includes being aware of where a branch will fall making sure I’m not positioned there. Although they are not heavy enough to crush me they could cause an injury with the chainsaw.

The hat that I wear (to keep my hair clean) often restricts my view if I look up suddenly. Today I have trailed using a shower cap instead of the hat in the photo, and found that it was better, so I will continue to use that for the time being.

Even moving from one branch to another can be dangerous. The ground is often wet and slippery.  Debris on the ground can obscure solid ground. Today I placed my foot close to a branch prior to making a cut and my foot sunk 400mm below what I expected.  I am in the habit of having the chain break on, when I move within the worksite, as a safety precaution with the chainsaw.

The duration of the chainsaw activity is restricted to 45 minutes due to the vibration and load exausting me. I will spend another hour clearing using the prunning saw and secatores, and painting the stumps. The remainder of my two hours is taken up sharpening and maintaining the chainsaw.

30 sept 2011:Today I came home from politech where I study OT full time and in the remaining time before the kids come home from school, I find myself writing about gorse rather than cutting it because it is too windy today. If I was to work today I know that the gorse is liable to be pushed in the wind and that it would be dangerous to use the chainsaw in these conditions. I have been cutting the gorse every Friday for weeks and know that next time I work on it people will see a dramatic difference, as I near the stage where I can freely work, and clear the space. This will make me feel great as previously I felt quite depressed looking out over a sea of yellow flowering prickly scrub. The gorse seemed to be oppressive growing closer and closer to the house. I am left with the knowledge that I can single handedly impact upon the most overgrown unkempt patch of land and enable regeneration of the native flora and fauna Thus it provides me with a sense of occupational competence. Others might look at this land in years to come and see the beauty of the land. I can already see that the bird life appreciate the work I’ve done as they can now fly tree to tree, where before the scrub was too dense for them to move within.

Jacobs, K., & Jacobs, L. (2009). Quick refrence journal for Occupational Therapy. Thorofare NJ: Slack Incorporated.