Table 3.
Ratios of principal tension and compression strains, and both shear‐strain criteria (material‐axis and maximum) during trial 4 (baseline with respect to plantar ‘tension region’ gauge). (a) Comparisons with respect to the distribution of each of the three strain modes at the plantar ‘tension region’ gauge vs. the two ‘compression region’ gauges (dorsal‐lateral and dorsal‐medial). (b) Comparisons at each of the five gauge locations in terms of these ratios: (1) compression : tension, (2) shear : tension, and (3) shear : compression
| (a) Dorsal and plantar gauges only | One strain mode (two locations) | |||
|---|---|---|---|---|
| Two gauge comparisons | Tension : Tension | Compression : Compression | M‐A Shear : M‐A Shear | Max Shear : Max Shear |
| Plantar : Dorsal‐Lateral |
3.81 P>D |
0.67 D>P |
1.75 P>D |
1.75 P>D |
| Plantar : Dorsal‐Medial |
3.26 P>D |
0.63 D>P |
0.85a
D>P |
 1.60aP>D |
| Dorsal‐Lateral : Plantar |
0.26 P>D |
1.50 D>P |
0.57 P>D |
0.57 P>D |
| Dorsal‐Medial : Plantar |
0.31 P>D |
1.59 D>P |
1.17a
D>P |
 0.62a
D>P |
| (b) All five gauges | Two strain modes (one location) | ||||
|---|---|---|---|---|---|
| Individual gauge locations | Compression : Tension | M‐A Shear : Tension | Max Shear : Tension | M‐A Shear : Compression | Max Shear : Compression |
| Dorsal‐lateral | 1.9 | 0.5a |
 2.9a
|
0.2a |
 1.5a
|
| Dorsal‐medial | 1.7 | 0.8a |
 2.7a
|
0.5a |
 1.6a
|
| Plantar | 0.3 | 0.2a |
 1.3a
|
0.6a |
 4.1a
,
b
|
| Medial | 1.9 | 2.2 | 2.9 | 1.2 | 1.5 |
| Lateral | 0.5 | 1.2 | 2.9 | 2.6 | 3.1 |
Cells highlighted in gray indicate the two gauge (dorsal vs. plantar) comparisons where the specific strain mode indicated was found to predominate in the dorsal ‘compression’ cortex.
M‐A, material axis; Max, maximum; P, plantar (‘tension region’) gauge; D = dorsal (‘compression region’) gauges.
Double‐headed arrows indicate cases where the ratio ‘inverts’ (becomes > 1.0 or < 1.0) in the paired comparison. This only involves ratios where the two different shear‐strain criteria are being considered.
As shown also in Table 1, this is the only case where maximum shear strains are high enough to call into question the view that the deer calcaneus is a simple ‘tension/compression’ (plantar cortex/dorsal cortex) bone. ‘Shear‐tension/compression’ might be more appropriate.