Movement (cont’d) - Using the information

“You can’t have a positive life with a negative mind.” – etsy.com

HOW ARE you this week? I hope you have been keeping up with your work. Remember, time lost can never be regained, so make the most of the time that you have now!

The objectives for this topic have been satisfied and we have shared a lot of information. The big question is, what can we do with this information? How well do we remember it? Can we manipulate it well enough so that it can be used to answer questions? Most of the questions that are on the exam papers, both Paper 01 and 02, do not ask for the regurgitation of this knowledge; they ask for the application of the knowledge to topical, often everyday issues, so be prepared! In this week’s lesson, we will be looking at ways that the knowledge we have gained can be used.

Let us begin by researching some of the mistakes that students make in answering questions on movement. These include:

INCORRECT SPELLING

How do you spell the following words: cartilage, synovial, humerus, and vertebra? Say them, then close your eyes and spell them. Now check your spelling; were you correct?

INCORRECT LABELLING OF A JOINT

Remember that one of the objectives specifies that you must learn to draw and label a synovial joint, so practise your drawing and learn the functions of the different parts of the joint.

INCORRECT IDENTIFICATION OF THE DIFFERENT TYPES OF JOINTS

This type of question can be phrased in many ways; learn to recognise the ways. You could be asked to differentiate between movement at a partially moveable joint and a hinge or ball and socket joint. Would you be stumped by this question or would you immediately recognise that the question is referring to the joints found in the wrist/ankle (gliding joints), or that found between the atlas and the axis (pivot), which are partially moveable joints, that of the elbow and knee (hinge)and that found between the scapula and the humerus, or the pelvis and the femur (ball and socket)? If you were able to, then you would be able to give the answer that movement in the partially moveable joint is limited or restricted when compared with movement at the elbow (hinge joint) or leg (ball and socket), which is much freer.

Let us go back to the lesson before the last one, the one showing movement in the forelimb. Take a good look at the diagram, Figure 1. Study the position of the bones, study the position of the muscles, and study the labels. What have you noticed? Did you notice that the antagonistic muscles are located opposite to each other and that the tendons which attach them to the bones are on different bones at the joint? Now get a sheet of typing paper and draw the diagram. How well did you do? Does your diagram look like the original? Probably not, because you have not been practising to do the drawing, have you? There is a good chance that you may be asked to reproduce this diagram in an exam. Then what will you do? It is also likely that the examiner could substitute the hindlimb for the forelimb that you have studied; even more cause for concern? Not necessarily so! The hindlimb is set up in the same way as the forelimb, only the names of the bones are different: the humerus is replaced by the femur, and the ulna and radius by the tibia and fibula. The muscles have the same arrangement of antagonistic pairs as in the forelimb; hence, if you can do one, you can do both!

Both the humerus and the femur are known as long bones; and be reminded that your syllabus requires you to have an annotated drawing of the humerus in your lab book!

Remember also that there are certain illnesses that are associated with bones and joints, and you need to be aware of these. These include:

RHEUMATOID ARTHRITIS

This occurs when the smaller joints of the body become inflamed. Tissue can grow into the space between the joint, making movements difficult; the joint may eventually become fused, hence preventing movement of any form.

OSTEOARTHRITIS

This is a disease which affects older people when the cartilage at the end of the bones is worn away. Remember that the cartilage acts as a shock absorber and prevents friction, so when it is worn or missing, movement becomes painful. If this happens with the hip bone, it can lead to decreased mobility in older persons. Obesity can also lead to reduction in mobility, since a large body mass can put a greater strain on the joints, in particular the hip, knee and ankle joints.

Some people lose bone mass as they age and this can also cause damage to the joints.

Additionally, you may be asked to give the functions of the different types of bone, but this should not be a problem since the answer just requires you to remember what you have learnt!

What do you need to do now?Go and practise drawing those bones!

Take care, until next week!