As part of the day-to-day work of orthopaedic pharmacists, it is necessary for them to know the correct way of taking measurements when fitting an orthosis. Since, on many occasions, patients can have anatomical and pathological characteristics that differ from the measurements in which orthoses are mass produced. In order to ensure an optimum fit and, therefore, certify that the orthosis will have the appropriate therapeutic/preventative effect.
In this article, we will review the basic concepts to be taken into account and their significance for the main types of orthosis.
We begin by mentioning that the quality and effectiveness of orthopaedic products is also determined by the means of production employed in their manufacture, the raw materials used and the degree of completion incorporated into them.
From this point of view, and also from the user’s perspective, we can differentiate between two main types: orthoses made from elastic fabric and those made from neoprene, although other materials exist.
These products include supports for the ankle, wrist, back, knee, elbow, etc.
Shapes, sizes, measurements and compression
The term measurements refers to the patient’s measurements. Shapes and sizes refer to the measurements of the orthosis.
Compression and sizing are closely linked because if an excessively large or small size is used, the compression is much lower or greater than what the orthosis should normally offer.
Necessary elements and tips for taking measurements:
- Well-lit and quiet fitting room
- Examining table and mirror
- Metal tape measure and goniometer to measure angles
- Measurements should be taken with the patient stripped down to underwear. When measuring a female patient for a dorsolumbar orthosis, she should keep her bra on.
- Do not keep the patient standing or in an uncomfortable position for too long during the process and, depending on the type of orthosis, the patient should be lying horizontally.
Reference points are always going to be relative due to malformations, conditions and injuries that change the relative location of these points and can result in erroneous measurements.
Geometric symbols are used in ortho-prosthetic measurement according to the manufacturer’s indications.
Method for taking the reference:
The circumference of the ankle is measured around both malleoli (internal and external). Measurement should be taken when the ankle is not swollen and 2 cm above the malleoli.
These are selected (except for those in one size already mentioned) according to the measurement of the circumference of the wrist, with the palm of the hand in a ventral position, around the radial styloid process.
Measurement is taken above and below the knee or around the circumference of the centre of the kneecap. The knee should not be swollen when measuring.
Back supports: measurement is taken around the circumference of the trochanter or abdomen depending on the model of orthosis.
The measurement in centimetres of the widest part of the elbow is taken as the reference.
There are different established methods, especially those relating to commercial brands or particular products that require a specific way of taking measurements, but, in general, all methods are similar, as the same reference points are used.
To this end, it is necessary to have sensitivity of palpation to find these anatomical points of reference, such as the olecranon, the greater trochanters of the femur and the malleoli of the ankle.
In summary, only orthoses that are supplied with the manufacturer’s sizes and corresponding measurements should be dispensed.
Orliman’s Technical Department