What is this challenge about?
The contestants are presented with a strikingly large thigh bone. The task is to find out the size of the person (or rather the giant) to whom this bone once belonged.
Materials: Bone with measurements (see below), tape measure, pencil, paper, human-sized skeleton.
Do you want to try it too?
The bone from the show (see photo above) is 77cm long. Now find out which bone it is by comparing it with the skeleton shown below:
Once you know, you can work out how big the giant is!
Infobox
The human-sized skeleton can help you find out which bone it is.
The bone in question is the thigh bone (femur): Its spherical upper (proximal) end is characteristic of a bone with large joint movement, in this case it forms the hip joint with the hip bones. There are only two ball-and-socket joints in the human body: the upper arm bone (humerus) forms the second. The humerus is similar to the femur. Both are long bones with a round and a flat end; however, the femur has an elongated tip on which the almost spherical extremity sits, which fits perfectly into the hip bone. The extremity of the humerus, on the other hand, is more hemispherical. The femur also bears the entire weight of the body and is therefore thicker and more stable than the humerus. It is the longest bone in our body.
Next, you need to measure your own femur and compare it with your overall height. The best way to measure your femur is to lift your knee and hold it towards the centre of your body: this will show you approximately where your femur starts at the hip joint and where it ends at the knee joint. These two measurements (thigh length and height) are best taken on different adult people. Normally, you should now realise that the height and length of the thigh are always in a ratio of 1:4. This means the height is always about 4 times the length of the thigh.
You can then simply multiply the length of the bone from the show by 4 to determine the size of the giant.
The femur should be about ¼ of the length of the human body. As the exact proportions are not the same for every body, a fairly large margin of error must be taken into account for this task.
Solution: The giant is 3 metres tall. Any number between 2.8 and 3.2 would also be correct.
Want to know how the contestants from the show mastered this challenge?
Then watch episode no. 9! (Will be released on 2.03)
What is the scientific background to this challenge?
Whether in medicine, forensics, anthropology or archaeology, bones are important in many professions. They can provide a wealth of information about the condition of the body and an individual's past. Height, age (through tooth development and bone resorption) and gender (through the bone structure of the pelvis and skull) can be estimated, but also more complex information such as the health status: some diseases change the bone structure, such as rheumatoid arthritis or metastases. Nutritional status also plays a role: bones can provide indications of malnutrition or specific deficiencies. One example of this is rickets (in children) or osteomalacia (in adults), which can be attributed to a lack of vitamin D.
Other genetic abnormalities such as Marfan syndrome can also be visible in the bone structures: Long skull, funnel or keel chest, tall stature....
In the fields of paediatrics and traumatology, bones can provide information on whether a child has suffered fractures or other injuries that cannot be explained by normal accidental trauma. Fractures can often be assessed by analysing fracture lines and healing processes.
Frequent physical strain can lead to changes in bone density or the shape of bones (e.g. in athletes).
Last but not least, the cause of a person's death can be determined in forensics: Injuries such as blunt force (e.g. from blows) or sharp force (e.g. from weapons) leave characteristic marks.
Fun facts:
- The femur is the longest bone in the human body.
- The stapes is the smallest bone in the human body. It is the third of the auditory ossicles in the middle ear of mammals. At 3 millimetres in diameter, it plays an important role in the transmission of sound waves.
- Bones can repair themselves: In the event of a fracture, new bone tissue forms to repair the damage (at least partially).
- Space osteoporosis: Astronauts who spend long periods in weightlessness lose bone mass (on average 1 to 2 % every month!). Bone atrophy occurs in the weightlessness of space, as the bones no longer have to support the body against gravity. When astronauts return to earth, their weakened bones are fragile and exposed to an increased risk of fracture.
- For most people, their height is as long as their arm span. The ratio between arm span and height is known as the monkey index and originates from the climbing scene. If your monkey index is greater than 1, you probably have an advantage when climbing.
- The hand is about as long as the face (from chin to forehead).
- Did you know that your feet are usually as long as your forearms?
A few impressions from the ninth episode
Author: Diane Bertel
Editor: Lucie Zeches (FNR)
Photos: Emmanuel Claude
