"physically constrained" is a perfectly valid phrase in written English.
You can use it any time you need to describe a situation where something is limited or held back by physical forces. For example, "The small space we had to work in was physically constrained and made it difficult to complete the project."
We reconstructed the seasonally unbiased and physically constrained Greenland temperature over the Holocene.
At such high altitudes, mountaineers are physically constrained by heavy clothing, and conversation is difficult and halting.
Yet both movies hinge on isolated, physically constrained men who are not what they seem, including, importantly, to themselves.
Here, we reconstruct seasonally unbiased and physically constrained Greenland Summit temperatures over the Holocene using argon and nitrogen isotopes within trapped air in a Greenland ice core (GISP2).
The Orbital Parameters Model (OPM) is a physically constrained model for geometrical correction of satellite images with dynamic geometry.
Our conclusion is that Badegoulian humans were not physically constrained by a familiar territory, but traveled and/or traded widely in their quest for suitable raw materials.
Smooth muscle is stiffer than its adjacent epithelium and often serves its morphogenetic function by physically constraining the growth of a proliferating epithelial layer.
Some of these landmarks physically constrain a resident's perception or movement and may thus make the use of space beyond the landmark too costly.
We don't like what he's saying because it offends our intuitions about what is fair and what is just, so we try to physically constrain him from doing so.
A basis function approach, which represents the design space by linearly combining the hydrodynamic performance coefficients of a diverse set of basis platform geometries, was taken as the most straightforward way of physically constraining the platform hydrodynamic performance.
It's less obvious that using a ruler and a pencil is actually a terrible way of ensuring that you cut two pieces the same length - the best way is to physically constrain your cutting arrangement so that you can only cut at one length: You can see a fairly scary-looking machine in the photograph above - it's called a 'mitre saw', and is really awesome at cutting exact angles in wood.
