The Relationship Between Linear Osteological and Radiographic Measurements of the Human Calcaneus and Talus

Abstract

Plain radiographs of the foot are a common form of examination in individuals when medical evaluation is indicated. Their availability makes them useful for studying human variation where large sample sizes are crucial. Calcaneal and talar morphology are critical in the understanding of human foot form and function, but few studies have examined the accuracy of linear measurements of these bones taken from radiographs. If linear measurements are to be used in quantitative analysis, their accuracy must first be demonstrated. For this study, 54 human feet from amputated limbs were imaged in standard radiographic views and skeletonized. Selected linear measurements were made on each skeletonized talus and calcaneus. Corresponding landmarks were identified on the radiographic images and the distances between these points determined. Using the measurements taken from the physical bone, the accuracy of the radiographic measurements was evaluated employing paired Student's t-tests and correlation analysis. Most measurements were not significantly different (P 0.05). Overall, the sagittal plane measurements were correlated (r 2 > 0.61-0.88, all P < 0.001) with the radiographic measurements; transverse plane measurements less so (r 2 5 0.20-0.63, P < 0.001). These results demonstrate that measurements from radiographic images provide useful information concerning both the calcaneus and talus, indicating that radiographs of living individuals can be evaluated quantitatively and compared to osteology collections of modern humans. This information can be applied to the understanding of functional anatomy of the modern human foot, interpreting the hominin fossil pedal record, and establishing identification in forensic analysis. Anat Rec,

Radiographic measurements of the talus and calcaneus in the adult pes planus foot type

“…While the beak of the cuboid and the sellar nature of the CCJ cannot be directly evaluated by the radiographic views used in this study, the CCJ, as represented in the lateral view by the angle formed by the distal anterior border and the longitudinal axis of the calcaneus (AALCALx) demonstrated an association with the medial longitudinal arch, thus providing useful information in categorizing foot type. Of note, the average AALCALx in this study (97.5°) is somewhat lower than those reported elsewhere: Berillon, (107.2°); Prang, (106°); Heard‐Booth, (109°); Agoada & Kramer, (105.5°) (from a different population than that used in this study). It should also be noted that the radiographically determined AALCALx measurement as described in this study is associated with that taken from the bone ( r 2 = .73 p = .001; Agoada & Kramer, ).…”

“…Of note, the average AALCALx in this study (97.5°) is somewhat lower than those reported elsewhere: Berillon, (107.2°); Prang, (106°); Heard‐Booth, (109°); Agoada & Kramer, (105.5°) (from a different population than that used in this study). It should also be noted that the radiographically determined AALCALx measurement as described in this study is associated with that taken from the bone ( r 2 = .73 p = .001; Agoada & Kramer, ).…”

“…The following lateral view angular calcaneal measurements were associated with foot type ( p ≤ .001) (Table ): the angle of the posterior facet (AIPTFCALx) ( r 2 = .33); Böehler's angle (BTACALx) ( r 2 = .34); the compression angle of the calcaneus (CACALx) ( r 2 = .44); the anterior angle of the calcaneus (AALCALx) ( r 2 = .41); and front angle of the calcaneus (FACALx) ( r 2 = .29). Note that each of these variables has demonstrated a significant relationship (all p 's ≤ .001) between radiographic and physical bone or photograph measurements (Agoada & Kramer, ). While AIPTFCALx, BTACALx, AALCALx, CACALx, and FACALx were all associated with foot type, after the Bonferroni correction only AALCALx and CACALx displayed a significant relationship between the angular measurement and foot type ( p ≤ .001).…”

“…Harcourt‐Smith et al () demonstrated differences in the body of the calcaneus in great apes when compared to modern humans, suggesting a functional relationship between calcaneal morphology and bipedal locomotion. Radiographic measurement of this variable was closely associated with that taken from the bone ( r 2 = .69 p ≤ .001; Agoada & Kramer, ).…”

“…The availability of weight‐bearing standardized radiographic images of the human foot taken for medical evaluation provides a large number of individuals for statistical analysis of such angular (and linear) relationships. The relationship between measurements taken from an image of the calcaneus and talus and the physical bones has been demonstrated (Agoada, ; Agoada & Kramer, ).…”