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ENSP/FIOCRUZ. The Cost of Lifestyle: Skeletal Markers of Occupational Stress (MOS) in Brazilian Prehistoric Coastal Populations Claudia Rodrigues-Carvalho. Above: Two shellmounds in Santa Catarina State: Figueirinha I and II. Photo: Gaspar. 2000.
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ENSP/FIOCRUZ The Cost of Lifestyle: Skeletal Markers of Occupational Stress (MOS) in Brazilian Prehistoric Coastal Populations Claudia Rodrigues-Carvalho
Above: Two shellmounds in Santa Catarina State: Figueirinha I and II. Photo: Gaspar. 2000. Right: Manitiba shellmound in Saquarema, Rio de Janeiro, during excavation. Photo: Lina Kneip collection. Museu Nacional/UFRJ
Markers of Occupational Stress (MOS) “Distinctive morphologies or true pathological alterations that can develop as a result of work-related activities” Capasso et al. 1999 • MOS can be used to investigate past groups workloads which expressed established labour divisions allowing, in some cases, specific activities reconstructions. MOS selected in present study: • Signs of articular degeneration (AD), osteoarthrosis indicator • Musculoskeletal Stress Markers (MSM)
Articular degeneration/Osteoarthrosis • Progressive articular degeneration evolving cartilage and subchondral bone, marginal exostosis and, finally eburnation in points were occur bone to bone contact.
Musculoskeletal Stress Markers • Physical stress markers associated to muscular activity overload expressed in muscle insertion sites. Include robusticity markers, stress lesions and ossifications (Hawkey & Merbs, 1995 ).
MOS studies in Brazilian coastal samples: general results • Articular degeneration (apendicular skeleton): • Frequencies of affected individuals vary among samples but it’s usually lower than 40%, with a few cases of intense damage. • Sex prevalence and more affected joints also vary among samples (Neves, 1984; Machado, 1992; Sorto et al., 1999). • Musculoskeletal studies: • Pattern of low occurrences of stress lesions and ossifications, • Moderate to mild robusticity grades prevailing and heavier workload in males (Mata, 2000; Scherer, 2002; Rodrigues-Carvalho et al. 2002). • Cabeçuda Shellmound (Santa Catarina State): data suggests low expressions of unilateral activities in whole series and the possibility that rowing among females wasn’t an usual activity (Teixeira, 2004).
Goals • Investigate the main workloads manifested in daily tasks in order to establish general patterns of physical demands. • Compare inter-series general patterns considering sex and age distribution. • Compare series general patterns and detail major similarities and singularities.
The skeletal series • In Rio de Janeiro State coast there are 6 areas with archaeological sites concentration (Tenório, 2003) • The present study selected 4 skeletal series from 3 areas: • Ilhote do Leste in Ilha Grande, the largest island in area 1. • Zé Espinho, in Guaratiba lowland, area 2. • Beirada and Moa, between the shore and the lagoon in Saquarema, area 4.
Ilhote do Leste, Ilha Grande (3.060 40 AP a 2.650 350 BP). Images from Tenório, 1999 and 2004. Image from Gaspar, 2000
Sambaqui de Zé Espinho, Guaratiba (1.180 +- 170 a 2.260 +- 160 BP) Map: Kneip, 1987. Photos: Lina Kneip collection. Museu Nacional/UFRJ
Saquarema City shellmounds: Beirada (4.520 +- 190 a 3.800 +- 190 BP) Moa (3.960 +- 190 AP e 3.610 +- 200 BP)
Beirada Photo: Lina Kneip collection. Museu Nacional/UFRJ Moa Moa Photos: Maura Imazio
Investigation proceedings • Analysis in apendicular skeleton only, also restricted to adults or late adolescents, from both sex. • Excluded any individual with multiple fractures or extensive pathological signs. Insertion muscle sites considered Articulations considered
Data Registration • Osteoarthrosis: intensity of articular alterations (Machado, 1984) • Grade 0: no signs of articular alterations; • Grade 1 (slight): porosities in articular surface and/or articular margins defined with sharper edges, eventual bone exostosis (<1mm); • Grade 2 (moderate): clear lipping evidence (≥1mm) and/or bone damage in articular area. • Grade 3 (intense): severe lipping (>2mm) and/or severe articular bone damage, eburnation.
MSM: robusticity grade, stress lesions and ossifications (Hawkey & Merbs. 1995; Hawkey. 1998) • Robusticity: • Grade 0 (none): no signs of robusticity; • Grade 1 (slight): slight indentation at the site attachment; • Grade 2 (moderate): roughening of the attachment site, well-defined surrounding margin; • Grade 3 (intense): deep indentation, clear defined margin of bone. Image from Hawkey, 1998.
Stress lesions: • Grade 0 (none): no lesions; • Grade 1 (slight): A shallow ‘furrow”, a pitting with litic-like appearance; • Grade 2 (moderate): pitting deeper and cover more surface area but never more than 5mm • Grade 3 (intense): pitting is marked, more than 3mm depth and 5mm in length. • Ossifications: • Grade 0 (none): no ossifications; • Grade 1 (slight): slight exostosis, less than 2mm from cortical surface; • Grade 2 (moderate): distinct exostosis that extends more than 2mm but less than 5mm; • Grade 3 (intense): exostosis extends more than 5mm from the surface of bone. Left image from Hawkey, 1998. Right image from Capasso, 1999, reprinted from Galera & Garralda,1993.
Results Overview • Considerable variability among individuals from the same sex and age interval. • The individual variability and the small series prevented a clear verification of relations between MOS and age. • Heavier workload for men. • Inter-group workload variability. • Heavier workload in Ilhote do Leste. • Low occurrence of side dominance. • General data for upper limbs suggests dominance of movements requiring arm adduction and rotation; forearm flexion, pronation and supination. • Arm and shoulder movements prevailed in Ilhote do Leste series, Zé Espinho and Beirada males; Forearm pronation prevailed in Moa series and in Zé Espinho females. In Beirada series forearm flexion were more pronounced; • General data for lower limbs suggests dominance of movements requiring hip extension, rotation, balance and knee flexion.
Results - AD/Osteoarthrosis • Prevalence of slight articular alterations (except for Ilhote do Leste). • Upper limbs more affected. • Mostly affected articular area: wrist. • Early onset for moderate degree: • 30-39 years in Beirada and Moa series; • 20-29 years in Zé Espinho and Ilhote do Leste.
Results – Articular Degeneration Graph 1. Beirada Shellmound. Distribution of articular degeneration grades in upper and lower limbs. Graph 2. Moa Shellmound. Distribution of articular degeneration grades in upper and lower limbs. . Graph 3. Zé Espinho Shellmound. Distribution of articular degeneration grades in upper and lower limbs. . Graph 4. Ilhote do Leste Shellmound. Distribution of articular degeneration grades in upper and lower limbs.
Graph 5. Beirada Shellmound. Distribution of moderate and intense AD grades. Graph 6. Moa Shellmound. Distribution of moderate and intense AD grades. Graph 7. Zé Espinho Shellmound. Distribution of moderate and intense AD grades. Graph 8. Ilhote do Leste Shellmound. Distribution of moderate and intense AD grades.
No AD Slight Moderate Intense Results – Articular Degeneration - Prevailing Grades Beirada Moa Zé Espinho Ilhote do Leste
Results - MSM – Robusticity • More developed areas: Pectoralis Major, Deltoideus, Braquialis, Biceps Brachii. Pronator Quadratus, Gluteus Maximus • Dominance of faint robusticity in females (except Ilhote do Leste series) • Dominance of moderate robusticity in males (and in Ilhote do Leste females) • Lower limbs with higher grades than upper limbs (except for Ilhote do Leste series): Gluteus Maximus effect.
Results - MSM – Stress Lesions • In females, only in Ilhote do Leste, 3 cases in Pectoralis Major, 2 in Teres Major. • In males: Moa, 1 case in pectoralis Major and Biceps; Zé Espinho, 1 case in Pectoralis Majos; Ilhote, 4 cases in Pectoralis Major, 1 case in Pronator Teres. • Special case: Gluteus Maximus in some individuals presented intense marks deep into bone cortex but with no litic-lesion appearance. This feature was observed in 10 individuals and wasn’t present in Beirada series and Zé Espinho males. • Results - MSM – Ossifications • In females – Beirada: 1 case in Triceps, mild; Ilhote: 1 case in Teres Major. • In males – Zé Espinho: 2 cases in Pectoralis Major, 1 case in Biceps Brachii.
Results - MSM Graph 9. Beirada Shellmound. MSM frequencies for upper and lower limbs. Graph 10. Moa Shellmound. MSM frequencies for upper and lower limbs. Graph 11. Zé Espinho Shellmound. MSM frequencies for upper and lower limbs. Graph 12. Ilhote do Leste Shellmound. MSM frequencies for upper and lower limbs.
None Slight Moderate Intense Results - MSM - Prevailing Grades Beirada Moa Ilhote do Leste Zé Espinho
None Slight Moderate Intense Results - Articular Degeneration X MSM - Prevailing grades Zé Espinho Beirada Moa Ilhote do Leste
Data commentaries & and conclusions Although the small series doesn’t allow direct inferences for the whole populations, the observations suggests some hypothesis to be tested in larger samples: • There’s individual variability in MOS. It suggests differences in daily workloads even for individuals in same sex and age categories. • Men were under heavier physical stress than women, but specific activities could be proposed only on larger series studies. • Low occurrence of side dominance suggests that bilateral activities were more frequent or intense than those with side preference. This was also observed in one Santa Catarina State series (Teixeira & Salles, 2005) and deserves detailed studies in other Brazilian shellmound series. • Ilhote do Leste females’ data raises the possibility that women in this series shared some heavier tasks with males. • The intense MOS pattern verified in Ilhote do Leste, in comparison with other series also suggests specials workload demands. This could be related to specialized tasks like axe production and frequent navigation in heavy seas (expected for both sex).
Data commentaries & and conclusions (continuation) • The low occurrences for intense AD, stress lesions and ossifications are shared with other Brazilian Shellmound series studied before. • The MOS patterns variation among series, specially the lower MOS intensities observed in Saquarema city series and the intense MOS in Ilhote do Leste, with distinct geographic insertions points out the need to detail in further studies the influence of particular environmental conditions on MOS. • In spite of heavier physical stress observed in Ilhote do Leste series, the MOS pattern suggests that these groups had a vigorous but not intensively stressful lifestyle. × × ×