Friday, June 9, 2017

Leg Armour Support - Pressure Bands

Leg Armour Support - Pressure Bands

Pressure and support principles behind the fabric or leather garments that support leg armour, hose or even modern stockings.

The best way for the human body to carry medium to light weights on the legs is to use pressure bands on the midrift. It allows full range of motion of the arms and the legs when done correctly.

The pressure bands need to be of ever decreasing pressure in order to provide comfort and movement. The downwards pressure of the borne weight is held mainly at the bottom, and then gradually lightened off as it gets higher. Weight on the shoulders reduces range of movement and the ability to raise the arms high above the shoulders, so should be at best zero, or the least amount possible.

In the diagram below, red and orange hold most pressure, yellow less pressure, and green (or above) significantly less pressure. The white line indicates the angle of a fitted garment. This white line is the edge of the 'cone segment' that holds the weight in place by shape.  

Anatomy man shows pressure bands with colour coding with ROYGBIV colour coding

This gentleman is wearing a light fitted sleeveless garment that has points to hold up his padded leg armour and likely also a steel over armour. The method by which the pressure is regulated is by the tightness of the lacing. at the bottom the lacing will be firmed, and it will gradually have less pressure as it goes upwards. Clever tailoring provides the angle in, and then an angle outwards - the point where these angles change is visible as the spacing of the laces, and a small fabric bulge. The upper section of the garment above the green zone is clearly holding less pressure, and this is acknowledged by the garment maker as the time consuming lacing has been abandoned for simple ties, which can easily take the lowered pressure and are easier to construct. 
Common usage terms for my group is purpoint for the sleeveless unpadded body garment and chausses for the padded leg armour garments.

The quilted hip hugging garment below skips the green pressure bands entirely and sits on and just above the hips. The lacing points are again used to to provide tightness at the bottom, less in the middle, and even less on the top. Two pairs of two suspension points spreads the lifting load across the garment.  Quilting provides more comfort that a single layer of cloth or leather. Lacing points are not the only options, straight one to one ties or strap and buckle can be used. 
This is a lendenier or armoured girdle. When done in one layer of cloth or leather, the common usage term for my contemporaries is a c-belt.

 This next garment is unpadded or lightly padded full jacket to be used under full plate armour. This was given as an example of that jacket, and also to show a few interesting points regarding fit and construction. I believe this garment will cause the operator discomfort, back pain, and lowered range of movement with the arms. I recognise that the wearer only has one piece of leg armour, but principles are displayed here that will hold even when the next leg is added. The red band of pressure is pulling the fabric out of shape, and causing a 'bunch up' of fabric. The necessary pressure banding of less and less pressure has not been achieved. there will be a narrow band of pressure causing a load on one specific vertebrae on the back. The band does not take the strain, so it will be shared by the shoulders. This can be seen by the blue circled bunching of fabric. If the banding was done correctly, the bunching would have been much lesser, and would have conformed with the circle seams around the shoulder. The white arrow indicate the straight up and down nature of the line of force. Even on the other side, the line of force is too up and down - it needs to be steeper and this needs to be achieved by more tightness at the lower points, and less while working upwards.

This garment is called and arming doublet by my  contemporaries.
This next garment is shown to illustrate that the principle have not changed into the modern era. The bands still exist, comfort will be gained by better usage of the pressure principles. This garment has the advantage of being constructed of modern stretch materials and having very little weight to support. The garment forms the same inverted cone section as all the other garments. It also allows free range of motion of the arms and legs.
This is called a modern garter belt.

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