Validation of CPM#1 compressibility in healthy volunteers in rest and after exercise

Chronic Exertional Compartment Syndrome (CECS) is one of the exercise-induced
lower leg pathologies. Recognition by patients and physicians is not optimal.
As a consequence, many patients are undiagnosed and are forced to stop their
sporting activities. To diagnose CECS, a doctor should be alerted by a
patient*s history and a physical examination. If both suggestive of CECS, an
invasive intra compartmental pressure measurement (ICPM) in the affected
compartment may be performed. During the ICPM a catheter is placed into the
muscle via a hollow needle. The ICPM is not flawless in terms of accuracy and
reproducibility and has a low intra-observer reproducibility. Moreover,
haematoma or other tissue damage may occur following an ICPM. Nevertheless,
this invasive ICPM is in 2022 still considered the *gold-standard* diagnostic
tool for CECS, in the absence of a better one.
A novel non-invasive tool for CECS is possibly provided by measuring muscle
tissue compressibility. The idea is, that muscle tissue with a high pressure
(as in CECS patients) requires more external force to compress, compared to
tissue with a low pressure. The study device used in this study, the CPM#1
device, is based on this principle. The CPM#1 device is non-invasive, not
painful, very user friendly, and the measurement can be executed as an *office
procedure* in a couple of minutes. This study will focus on determining the
reliability of the device in healthy volunteers. The optimal way to perform
these measurements are however not standardized. Overall there have been two
measurement methods reported to determine the compartment length. One orients
the measurement towards the interosseous membrane between the tibia and fibula
('interosseous'), the other oerients at the intersection of the interosseous
membrane to the tibia ('notch'). The orientation which has been used mostly in
recent literature for the ultrasound measurements is the notch.

The primary objective is
- To clinically validate the inter-observer reliability of compressibility
measurements with the CPM#1 device during rest in healthy volunteers.

This study is a clinical performance validation pilot with the CPM#1 device
that is tested in healthy volunteers. There will only be one study arm, no
comparator, and no randomization. A second session will be implemented to also
study the orientation towards the interosseous membrane after exercise, as
preliminary analyses showed a higher than expected difference between the two
orientations.

Healthy subjects will undergo several compressibility measurements, both before
and after a treadmill exercise. They will also complete a NIAPS (Netwerk
Inspannings Afhankelijke PijnSyndromen) questionnaire and an *experience*
questionnaire. The harm associated with the CPM#1 device is none. However, the
subjects will not benefit from this study.