Methods for non-pathological articular modification collection

Non-pathological articular modifications indicate changes in activity patterns by means of highlighting alterations to posture adoption. In addition, the possibility that Islamic individuals undertook ritual prayer may have created Islamic/Visigothic differences in articular modifications. As weight-bearing joints are more likely to have articular modifications (Trinkaus 1975), the lower body was examined rather than the upper body.

A high prevalence of tibial and talus squatting facets was identified during a pilot study of the Écija material, possibly as a result of kneeling during prayer or daily activities with ankle hyperdorsiflexion (Inskip 2009). During prayer (salat), an individual moves through a set of postures which could potentially alter joint surfaces (see section

2.2.2.1). Observers kneel with the toes hyperdorsiflexed and the ankle hyperdorsiflexed (see figure 6.7) to keep the heel vertical. If salat was being undertaken by all members of the community, then a higher prevalence of kneeling and squatting modifications

could be expected in the

pected in the Écija group than in the Visigothic group.

odifications induced by kneeling or squatting activity, sophalangeal joints were examined. As Trinkaus (1975) s

weight during kneeling, it was not included in these ubsections highlight and clarify the modifications chosen

ower leg position during kneeling phase of salat (adapted

tions: osteochondritic imprints, tibial imprints and vas

knee flexion, three modifications were examined;

e femoral condyles, tibial imprints on the supracondylar s ese were selected based on research outlined in section 4.

marks are imprints or flattening on the superior-infer et al. 1999, Kostick 1963, Trinkaus 1975) and wer on the medial and lateral condyles of both femora f the modifications differed between comparison groups,

print), n (new bone growth) or f (facet) if present osteochondritic imprint.

Accordingly, to activity, the knee, ankle and aus (1975) suggests that the hip d in these analyses. The

if present. See figure 6.8 for

Figure 6.8 Imprint on the femoral condyle (author’s own photograph).

Related modifications are tibial imprints on the supracondylar surface of the femur. The tibial plateau is forced into the supracondylar surface of the femur when the knee is hyperflexed. Tibial imprints, following Capasso et al. (1999), were identified on the medial and lateral supracondylar surfaces of both femora (figure 6.9). If present, they were scored as either i (imprint), n (new bone growth) or e (extension) to the condylar surface.

Figure 6.9 Tibial imprint on the medial condyle (author’s own photograph).

Vastus notches

Vastus notches are thought to be caused by tension of the vastus lateralis tendon during persistent kneeling (Finnegan 1978) (Figure 6.10). Vastus notches were scored

following Finnegan (1978). The notch borders had to be smooth. If the notch was small and the border was only just compromised, it was scored as 1 (small). If the notch was larger, then it was scored as 2 (large). This permitted the observation of whether there

was any size difference i

ce in the notch between groups which indicated iffered by group.

grades of vastus notch, A) absent (note sharp edge, B) n photograph)

rsiflexion modifications: squatting facets on the tibia a

tification of ankle hyperdorsiflexion, three squatting face lateral tibial and the talus squatting facets. All ar ith habitual squatting (Trinkaus 1975).

tibial squatting facet was described by Finnegan (1978) further by other authors. It was therefore scored as pre present when ‘the inferior articular surface is extended in

egan 1978:25).

tibial squatting facet, while noted by Barnett (1954), was b as being where the ‘inferior articular surface exte transverse depression’. It has been general practice to sco nt or absent (e.g. Brothwell 1981, Mays 2007). However S ariation existed in the facet size and argued that lateral tib cored differently as this variation may indicate posture dif ble to highlight the exact cause, intergroup facet size varia adoption of posture type or duration and therefore merits y, the facets were scored on a scale of 0–3, based on size (

for a visual representation of these facets.

ich indicated whether kneeling

, B) 1= small C) 2 = large

he tibia and talus

quatting facets were examined:

. All are thought to be

gan (1978) but has not really scored as present or absent.

s extended into the medial

was better described by r surface extends into the lateral

ractice to score the facet as . However Satinoff (1972)

Table 6.6 Written descriptions for the identification of tibial squatting facets

Tibial squatting Facet type Visible description

Absent No facet observable

1 A small indent made in the lateral anterior contour of the distal tibia

2 A large clearly demarcated facet on the lateral anterior contour of the fossa.

3 A large facet that impinges on the distal shaft of the tibia.

Figure 6.11 Tibial Facet types. A) facet type 1. B) facet type 2. C and D) facet type 3.

(author’s own photographs)

Talus squatting facets have been subject to greater attention than tibial squatting facets.

Although Barnett (1954) described five talar facets, only one was associated with

prolonged contact between the tibia and talus (the lateral talus squatting facet (see figure 6.12)). Importantly, the lateral squatting facet has been demonstrated by modern clinical studies to be related to ankle hyperdorsiflexion (Singh 1959). As the only clear

definition of the talar facet, Barnett’s (1954) description was used here, with facet identification requiring it to be clearly demarcated from the trochlear surface.

D

A B C

Figure 6.12 A) Position of the lateral talar squatting facet (adapted from Barnett 1954:510) B) Facet on skeletal material from Écija (author’s own photograph)

Research by Boulle (2001a) has indicated that the talar squatting facet can appear in two forms; normal (congenital) or due to pressure (induced during life) (see figure 6.13). If Islamic prayer was undertaken from the earliest periods of Islamic rule, the presence and type of facet may permit identification of increasing conversion in the early phases of Islamic occupation in Spain. Therefore the nature of facet was recorded following Boulle (2001a) as absent, pressure or congenital. Table 6.7 provides descriptions of pressure and congenital facets as used in this research. Also see figure 6.13 for x-ray images of a congenital and a pressure facet, and a talus with no facet, and 6.14 for dry bone images.

Figure 6.13 X-ray of lateral squatting facets. Right normal, left pressure facet (Boulle 2001a:347)

A B

Figure 6.14 A) congenital facet B) dry bone pressure facet. C) Absence of facet.

(author’s own photograph)

Table 6.7 Descriptive criteria for pressure and congenital facets.

Talar Squatting

facet Visual description

Congenital A smooth clearly demarcated facet (figure 6.14a)

Pressure A rough raised facet which may have exostosis (figure 6.14b) Absent No modification present on talar neck (figure 6.14c)

Metatarsal hyperdorsiflexion: Metatarsal facet extensions and phalangeal wedging.

To identify metatarsal hyperdorsiflexion, two modifications were examined: metatarsal facet extensions and phalangeal wedging. Facet extensions on all distal dorsal surfaces of the metatarsals have been related to prolonged hyperdorsiflexion of the toes at the metatarsophalangeal joint (Capasso et al. 1999:142). During prayer, an individual is required to position the heel superiorly, meaning that the toes are hyperdorsiflexed (see figure 6.15). Following the only published method that exists for recording this

modification, facet extensions were identified using descriptions in Ubelaker (1979) and scored as absent or present. To be present, the articular facet extends beyond the

original border of the distal joint surface and onto the superior aspect of the metatarsal shaft. See figure 6.16 for an example of articular extension.

B C

A

Figure 6.15 hyperdorsifl

hyperdorsiflexion of the ankle and metatarsophalangeal j :683)

Extension to the articular border of metatarsal 3 (author’s

aced on the superior surface of the first proximal phalanx lexion of the first metatarsophalangeal joint creates a bony

from the bone surface on the superior portion of proxima d following the only method available (Ubelaker 1979). P undergo morphological change to the proximal joint surfac te for persistent hyperdorsiflexion of the metatarsophalan int surface becomes wedged dorsally, allowing an upward was identified following Molleson (1989) and was visible the edge of the proximal phalanges. Like extensions to th wedging was scored as absent or present (see figure 6.17 f th dorsal wedging). Where phalanges were not bagged sep

et al. (2011). ng an upward inclination of the

was visible as superior tensions to the metatarsals,

igure 6.17 for an image of a t bagged separately, they were

Figure 6.17 An example of phalangeal wedging (author’s own photograph) 6.4.2.2 Statistical analysis of non-pathological articular modifications

Before the comparisons outlined in 6.3.1 could be made, it was necessary to make the data comparable between groups. A calculation of modification prevalence was

undertaken by adding the total number of joints with articular modification and dividing the sum by the total number of observed joints x 100. As the data was non-parametric (not normally distributed) and categorical, the statistical significance of any differences between two categories was assessed using a Fisher’s exact test. Where multiple categories existed, a chi-squared test was applied. In tests with multiple modifications, some observations were removed from the chi-squared test when observed values were

‘0’, as these violate the rules of the test and create unreliable P values.

6.4.3 Osteoarthritis