However, only the slightest trace of rational theory, collateral test results or application techniques have been reported in open literature.
If the technological variability (simultaneous tests) is subtracted from the total within-subject variability (collateral tests), the biological variability remains.
In comparison, the respective CV values from the collateral tests in this current study of 3.8, 4.0, and 4.5 % are all predictably lower since the variability measured during two sections of the same steady-state on the same day (collateral test), will be lower than that seen during two separate steady-states measured across two different days (Crouter-study).
The simultaneous tests demonstrated that the inter-unit technological error equated to ~1.5 % CV and ~2.1 % APE, thus the biological error within the collateral tests amounted to ~3.5 % CV and ~4 % APE.
Total within-subject variation (biological + technological) was determined from the collateral tests, but the unique inter-unit variability (technological error between identical systems) was shown by the simultaneous tests.
These results suggest that under very well controlled test retest situations (i.e., our collateral tests, that involved minimal biological error due to measurements taken within the same steady-state bout, plus minimal technological error due to duplicate ParvoMedics systems), the total variation between two automated gas analysis systems can provide a CV <3 % at high work rates.
This measurable biological variation may have been due to a slight upward drift in the metabolic rate due to the relatively slow kinetic change in core body temperature, as heart rate also showed a small mean APE difference of 3.3 % during the collateral tests (compared to a trivial 0.3 % for the simultaneous tests).
This added biological error was due to the non-simultaneous sampling of inherently imperfect steady-state measurements of human respiration (the collateral test), as opposed to using ideal steady-state conditions generated by mechanical metabolic calibration systems (Gore et al. 1997; Vogler et al. 2010).
Both patients underwent standard clinical examination (Lachman Test, anterior & posterior drawer Test, medial and lateral collateral ligament test, mensicus test, palpation of posterolateral aspect of the knee) and radiographic diagnostics such as ultrasound, plain radiographs (a.p. and lateral view) and MRI.
Clinical examination using Lachman's test, the drawer test and the collateral stress test have confirmed a stable knee joint.
