SKELETAL MORPHOLOGY OF THE HUMAN HAND AS APPLIED IN FORENSIC ANTHROPOLOGY

Transcription

1 SKELETAL MORPHOLOGY OF THE HUMAN HAND AS APPLIED IN FORENSIC ANTHROPOLOGY NADIA NAVSA Thesis submitted in fulfillment of the requirements for the degree PhD Anatomy In the Faculty of Health Sciences, University of Pretoria, Pretoria 2010 University of Pretoria i

2 DECLARATION I declare that this thesis is my own unaided work. It is being submitted for the degree of Doctor of Philosophy in Anatomy at the University of Pretoria, Pretoria. It has not been submitted before for any degree or examination in any other University.... Nadia Navsa day of.2010 ii

3 TABLE OF CONTENTS List of figures List of tables Abstract Opsomming Acknowledgements Page xi xiii xvii xviii xix CHAPTER 1: INTRODUCTION General introduction Aims Hypotheses 3 CHAPTER 2: LITERATURE REVIEW - MORPHOLOGY OF THE HAND BONES Introduction and general anatomical descriptions Literature review Metacarpals Phalanges 11 CHAPTER 3: LITERATURE REVIEW STATURE DETERMINATION Introduction Literature review Historical background Studies on prehistoric material Bones used to estimate stature Methods used in estimating stature Effect of age on stature 36 iii

4 3.2.6 Living stature versus cadaver stature South African studies 39 CHAPTER 4: LITERATURE REVIEW - SEX DETERMINATION Introduction Literature review Manifestation of sexual dimorphism in the skeleton Manifestation of sexual dimorphism in bones of the human hand Sexual dimorphism in the South African population 49 CHAPTER 5: MATERIALS AND METHODS Materials Pretoria Bone Collection Methods Preparation of the dissected hand bones for identification and siding Problems which arose throughout the preparation of the dissected hand bones for identification and siding Measurements of the hand bones Measurements of the humerus, radius, ulna, femur and tibia Statistical analysis Stature determination Sex determination 63 CHAPTER 6: RESULTS - MORPHOLOGY OF THE HAND BONES General introduction Morphology of the first metacarpal Introduction 72 iv

5 6.2.2 Shaft or body Head Base Siding Morphology of the second metacarpal Introduction Shaft or body Head Base Siding Morphology of the third metacarpal Introduction Shaft or body Head Base Siding Morphology of the fourth metacarpal Introduction Shaft or body Head Base Siding Morphology of the fifth metacarpal Introduction Shaft or body 102 v

6 6.6.3 Head Base Siding Morphology of the first proximal phalanx Shaft or body Head Base Siding Morphology of the second proximal phalanx Shaft or Body Head Base Siding Morphology of the third proximal phalanx Shaft or body Head Base Siding Morphology of the fourth proximal phalanx Shaft or body Head Base Siding Morphology of the fifth proximal phalanx Shaft or body 128 vi

7 Head Base Siding Morphology of the second middle phalanx Shaft or body Head Base Siding Morphology of the third middle phalanx Shaft or body Head Base Siding Morphology of the fourth middle phalanx Shaft or body Head Base Siding Morphology of the fifth middle phalanx Shaft or body Head Base Siding Morphology of the first distal phalanx Shaft or body 152 vii

8 Head Base Siding Morphology of the second distal phalanx Shaft or body Head Base Siding Morphology of the third distal phalanx Shaft or body Head Base Siding Morphology of the fourth distal phalanx Shaft or body Head Base Siding Morphology of the fifth distal phalanx Shaft or body Head Base Siding 174 CHAPTER 7: RESULTS - MEASUREMENTS Intra- and interobserver repeatability tests 177 viii

9 CHAPTER 8: RESULTS DESCRIPTIVE STATISTICS, PEARSON S CORRELATION ANALYSIS AND STATURE DETERMINATION Introduction Descriptive statistics for hand bones of males and females Descriptive statistics for hand bones of South African whites and blacks Descriptive statistics for the humerus, radius, ulna, femur, tibia Determination of stature Pearsons correlation coefficient Correlation results for males Correlation results for females Regression analysis direct and stepwise procedures Regression analysis in South African males Metacarpals Proximal phalanges Middle phalanges Distal phalanges Regression analysis in South African females Metacarpals Proximal phalanges Middle phalanges Distal phalanges Calculation of regression equations 197 CHAPTER 9: RESULTS SEX DETERMINATION Introduction 235 ix

10 9.2 Metacarpals Proximal phalanges Middle phalanges Distal phalanges 246 CHAPTER 10: DISCUSSION Introduction Research sample Non-metric analysis Metric analysis Morphology of the hand bones Stature determination Sex determination 281 CHAPTER 11: CONCLUSIONS Morphology of the hand bones Stature determination Sex determination 292 REFERENCES 293 x

11 List of figures Figure 2.1: Figure 2.2: Figure 2.3: Figure 2.4: Dorsal (A) and palmar (B) view of metacarpals (MC) 1 to 5 of the right (R) hand 15 Dorsal (A) and palmar (B) view of proximal phalanges (PP) 1 to 5 of the right (R) hand 16 Dorsal (A) and palmar (B) view of middle phalanges (MP) 2 to 5 of the right (R) hand 17 Dorsal (A) and palmar (B) view of distal phalanges (DP) 1 to 5 of the right (R) hand 18 Figure 2.5: Figure 2.5: Siding techniques for the manual proximal (1-5) and intermediate (2-3) phalanges [Taken from Case DT and Heilman J International Journal 0f Osteoarchaeology 16: Copyright: 2006 John Wiley & Sons, Ltd.] 19 Figure 2.6: Siding techniques for the manual intermediate (4-5) and distal phalanges (1-5) [Taken from Case DT and Heilman J International Journal 0f Osteoarchaeology 16: Copyright: 2006 John Wiley & Sons, Ltd.] 20 Figure 5.1: Paired hands in calico bags for boiling (a), hand after boiling (b), disarticulation and cleaning of individual bones (c), calico bag with 30 pockets for individual bones ready for defatting process (d), hand bones being air-dried (e), labelling of individual bones (f) 65 Figure 5.2: Palmar view of metacarpal I - thumb (m-l = medial lateral measurement) 66 Figure 5.3: Lateral view of metacarpal I - thumb (d-p = dorsal palmar measurement) 66 Figure 5.4: Palmar view of metacarpal II - index finger (m-l = medial lateral measurement) 66 Figure 5.5: Lateral view of metacarpal II - index finger (d-p = dorsal palmar measurement) 66 Figure 5.6: Palmar view of metacarpal III - middle finger (m-l = medial lateral measurement) 67 Figure 5.7: Lateral view of metacarpal III - middle finger (d-p = dorsal palmar measurement) 67 Figure 5.8: Palmar view of metacarpal IV - ring finger (m-l = medial lateral measurement) 67 Figure 5.9: Lateral view of metacarpal IV - ring finger (d-p = dorsal palmar measurement) 67 Figure 5.10: Palmar view of metacarpal V - little finger (m-l = medial lateral measurement) 68 Figure 5.11: Lateral view of metacarpal V - little finger (d-p = distal palmar measurement) 68 Figure 5.12: Palmar view of proximal phalanx - index finger (m-l = medial lateral measurement) 68 Figure 5.13: Lateral view of proximal phalanx - index finger (d-p = distal palmar measurement) 68 Figure 5.14: Palmar view of middle phalanx - index finger (m-l = medial lateral measurement) 69 Figure 5.15: Lateral view of middle phalanx - index finger (d-p = dorsal palmar measurement) 69 xi

12 Figure 5.16: Palmar view of distal phalanx - index finger (m-l = medial lateral measurement) 69 Figure 5.17: Lateral view of distal phalanx - index finger (d-p = dorsal palmar measurement) 69 Figure 5.18: Maximum length measurement of the left humerus 70 Figure 5.19: Maximum length measurement of the left radius 70 Figure 5.20: Maximum length measurement of the left ulna 70 Figure 5.21: Maximum length measurement of the left femur 71 Figure 5.22: Maximum length measurement of the left tibia 71 Figure 6.1: Morphology of the right (R) and left (L) first metacarpal 80 Figure 6.2: Morphology of the right (R) and left (L) second metacarpal 89 Figure 6.3: Morphology of the right (R) and left (L) third metacarpal 95 Figure 6.4: Morphology of the right (R) and left (L) fourth metacarpal 101 Figure 6.5: Morphology of the right (R) and left (L) fifth metacarpal 107 Figure 6.6: Morphology of the right (R) and left (L) first proximal phalanx 112 Figure 6.7: Morphology of the right (R) and left (L) second proximal phalanx 117 Figure 6.8: Morphology of the right (R) and left (L) third proximal phalanx 122 Figure 6.9: Morphology of the right (R) and left (L) fourth proximal phalanx 127 Figure 6.10: Morphology of the right (R) and left (L) fifth proximal phalanx 132 Figure 6.11: Morphology of the right (R) and left (L) second middle phalanx 137 Figure 6.12: Morphology of the right (R) and left (L) third middle phalanx 141 Figure 6.13: Morphology of the right (R) and left (L) fourth middle phalanx 146 Figure 6.14: Morphology of the right (R) and left (L) fifth middle phalanx 151 Figure 6.15: Morphology of the right (R) and left (L) first distal phalanx 156 Figure 6.16: Morphology of the right (R) and left (L) second distal phalanx 161 Figure 6.17: Morphology of the right (R) and left (L) third distal phalanx 166 Figure 6.18: Morphology of the right (R) and left (L) fourth distal phalanx 171 Figure 6.19: Morphology of the right (R) and left (L) fifth distal phalanx 176 xii

13 List of tables Table 2.1: Additional siding techniques for the manual phalanges by Case and Heilman (2006) (PP=proximal phalanx, IP-intermediate phalanx) 21 Table 2.2: Additional siding techniques for the manual phalanges by Ricklan (1988) (PP=proximal phalanx, IP-intermediate phalanx, DP-distal phalanx) 22 Table 7.1: Table 7.2: Paired t-test statistics for the intra-observer test using the randomly selected bones of the thumb and little finger. All 7 dimensions of these bones are shown below. The measurements recorded by the original observer (O) were repeated by the second observer (L) at a different time 179 Paired t-test statistics for the inter-observer test using the randomly selected bones of the thumb and little finger. All 7 dimensions of these bones are shown below. The measurements recorded by the original observer (O) were repeated by the second observer (L) at a different time 180 Table 8.1a: Descriptive statistics comparing mean values (mm) of metacarpals (MC) 1 to 3 between males and females in South African whites and blacks 200 Table 8.1b: Descriptive statistics comparing mean values of metacarpals (MC) 4 and 5 between males and females in South African whites and blacks 201 Table 8.2a: Descriptive statistics comparing mean values (mm) of proximal phalanges (PP) 1 to 3 between males and females in South African whites and blacks 202 Table 8.2b: Descriptive statistics comparing mean values (mm) of proximal phalanges (PP) 4 and 5 between males and females in South African whites and blacks 203 Table 8.3a: Table 8.3b: Descriptive statistics comparing mean values (mm) of middle phalanges (MP) 2 to 4 between males and females in South African whites and blacks 204 Descriptive statistics comparing mean values (mm) of the fifth middle phalanx (MP) between males and females in South African whites and blacks 205 Table 8.4a: Descriptive statistics comparing mean values (mm) of distal phalanges (DP) 1 to 3 between males and females in South African whites and blacks 206 Table 8.4b: Descriptive statistics comparing mean values (mm) of distal phalanges (DP) 4 and 5 between males and females in South African whites and blacks 207 Table 8.5a: Descriptive statistics comparing mean values (mm) of metacarpals (MC) 1 to 3 between whites and blacks in South African males and females 208 Table 8.5b: Descriptive statistics comparing mean values (mm) of metacarpals (MC) 4 and 5 between whites and blacks in South African males and females 209 Table 8.6a: Descriptive statistics comparing mean values (mm) of proximal phalanges (PP) 1 to 3 between whites and blacks in South African males and females 210 Table 8.6b: Descriptive statistics comparing mean values (mm) of proximal phalanges (PP) 4 and 5 between whites and blacks in South African males and females 211 xiii

14 Table 8.7a: Table 8.7b: Descriptive statistics comparing mean values (mm) of middle phalanges (MP) 2 to 4 between whites and blacks in South African males and females 212 Descriptive statistics comparing mean values (mm) of the fifth middle phalanx (MP) between whites and blacks in South African males and females 213 Table 8.8a: Descriptive statistics comparing mean values (mm) of distal phalanges (DP) 1 to 3 between whites and blacks in South African males and females 214 Table 8.8b: Table 8.9: Table 8.10: Table 8.11: Table 8.12: Table 8.13: Table 8.14: Table 8.15: Table 8.16: Table 8.17: Table 8.18: Table 8.19: Descriptive statistics comparing mean values (mm) of distal phalanges (DP) 4 and 5 between whites and blacks in South African males and females 215 Descriptive statistics comparing mean values (mm) of long bone lengths between males and females in South African whites 216 Descriptive statistics comparing mean values (mm) of long bone lengths between males and females in South African blacks 216 Descriptive statistics comparing mean values (mm) of long bone lengths between males and females of the South African population 216 Pearsons correlation coefficients between the bones of the hand (metacarpals and phalanges) and the long bones (humerus, radius, ulna, femur tibia) in South African males 217 Pearsons correlations between the bones of the hand (metacarpals and phalanges) and long bones (humerus, radius, ulna, femur tibia) in South African females 218 Direct and stepwise regression showing the sequence of variable entry of metacarpals (MC) 1 to 5 into the analysis and standard error of estimates (SEE) (mm), R and R 2 to estimate the length (mm) of a long bone in South African males 219 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) of metacarpals (MC) 1 to 5 to estimate the length (mm) of a long bone in South African males 220 Direct and stepwise regression showing the sequence of variable entry of proximal phalanges (PP) 1 to 5 into the analysis and standard error of estimates (SEE) (mm), R and R 2 to estimate the length (mm) of a long bone in South African males 221 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of proximal phalanges (PP) 1 to 5 to estimate the length (mm) of a long bone in South African males 222 Direct and stepwise regression showing the sequence of variable entry of middle phalanges (MP) 2 to 5 into the analysis and standard error of estimates (SEE) (mm), R and R 2 to estimate the length of a long bone in South African males 223 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of middle phalanges (MP) 2 to 5 to estimate the length (mm) of a long bone in South African males 224 xiv

15 Table 8.20: Table 8.21: Table 8.22: Table 8.23: Table 8.24: Table 8.25: Table 8.26: Table 8.27: Table 8.28: Table 8.29: Direct and stepwise regression showing the sequence of variable entry of distal phalanges (DP) 1 to 5 into the analysis and standard error of estimates (S.E.E), R and R 2 to estimate the length of a long bone in South African males 225 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of distal phalanges (DP) 1 to 5 to estimate the length (mm) of a long bone in South African males 226 Direct and stepwise regression showing the sequence of variable entry of metacarpals (MC) 1 to 5 into the analysis and standard error of estimates (SEE), R and R 2 to estimate the length (mm) of a long bone in South African females 227 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of metacarpals (MC) 1 to 5 to estimate the length (mm) of a long bone in South African females 228 Direct and stepwise regression showing the sequence of variable entry of proximal phalanges (PP) 1 to 5 into the analysis and standard error of estimates (SEE), R and R 2 to estimate the length (mm) of a long bone in South African females 229 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of proximal phalanges (PP) 1 to 5 to estimate the length (mm) of a long bone in South African females 230 Direct and stepwise regression showing the sequence of variable entry of middle phalanges (MP) 2 to 5 into the analysis and standard error of estimates (SEE) (mm), R and R 2 to estimate the length (mm) of a long bone in South African females 231 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of middle phalanges (MP) 2 to 5 to estimate the length (mm) of a long bone in South African females 232 Direct and stepwise regression showing the sequence of entrance of distal phalangeal (DP) 1 to 5 variables into the analysis and standard error of estimates (SEE) (mm), R and R 2 to estimate the length (mm) of a long bone in South African females 233 Direct and stepwise regression coefficients (slope and constant) and standard error of estimates (SEE) (mm) of distal phalanges (DP) 1 to 5 to estimate the length (mm) of a long bone in South African females 234 Table 9.1: Discriminant function analysis of metacarpals 1 to 5 for South Africans 249 Table 9.2: Table 9.3: Table 9.4: Canonical discriminant function coefficients of metacarpals (MC) 1 to 5 for South Africans 250 Sexing accuracy of metacarpals 1 to 5 of South Africans. Percentage of correct group membership and cross-validation 251 Discriminant function analysis of proximal phalanges 1 to 5 for South Africans 252 xv

16 Table 9.5: Table 9.6: Table 9.7: Table 9.8: Table 9.9: Canonical discriminant function coefficients of proximal phalanges (PP) 1 to 5 for South Africans 253 Sexing accuracy using proximal phalanges 1 to 5. Percentage of correct group membership and cross-validation 254 Discriminant function analysis of middle phalanges 2 to 5 for South Africans 255 Canonical discriminant function coefficients of middle phalanges (MP) 2 to 5 for South Africans 256 Sexing accuracy of middle phalanges 2 to 5 of South Africans. Percentage of correct group membership and cross-validation 257 Table 9.10: Discriminant function analysis of distal phalanges 1 to 5 for South Africans 258 Table 9.11: Table 9.12: Canonical discriminant function coefficients of distal phalanges (DP) 1 to 5 for South Africans 259 Sexing accuracy of distal phalanges 1 to 5 of South Africans. Percentage of correct group membership and cross-validation 260 xvi

17 ABSTRACT The lack of detailed descriptions makes positive identification of individual bones of the human hand difficult. In some instances, labelled photographs and line diagrams depicting a few anatomical features are available in the literature while in other cases, unlabelled photographs and diagrams are provided. Textbooks generally describe each hand bone as having a head, shaft and base. The morphology of metacarpals is more commonly described than that of the phalanges. Thus, identification and siding of hand bones are rare, which excludes them from use in many forensic cases. Forensic anthropological studies also include the determination of demographic characteristics such as stature and sex. Parts of the human skeleton that are accurate predictors in determining stature and sex include the skull, pelvis, femur and tibia. Hand bones are often excluded from such studies due to their relatively small size and poor preservation. The aims of this study were firstly, to provide detailed morphological descriptions of metacarpals and phalangeal bones of the human hand; secondly, to develop regression formulae for stature using the hand bones and thirdly, to develop discriminant function formulae in which the hand bones can be used to determine the sex of an unknown individual. The study comprised 200 sets of hands of South African individuals. The results indicate that there are morphological features of individual bones of the human hand that can be used to identify and side them. Regression formulae have been devised whereby the length of a hand bone can be regressed to that of a long bone, which in turn can then be used to determine stature. The sexing accuracy, using the bones of the hand, is high for males and females. Average accuracies recorded were more than 80% in most cases, and more than 75% in all cases. Analyses of human hand bones can thus add valuable information when assessing skeletons of unknown individuals. xvii

18 OPSOMMING Weens die gebrek aan uitvoerige beskrywings, is dit moeilik om afsonderlike beentjies van die menslike hand positief te identifiseer. Soms is daar geannoteerde foto s en lyndiagramme in die literatuur beskikbaar, wat n paar anatomiese eienskappe uitbeeld, maar in ander gevalle is die fotos en lyndiagramme onbenoem. In handboeke word elke handbeentjie gewoonlik beskryf as synde met n kop, skag en basis. Die morfologie van die metakarpaalbene word meer dikwels beskryf as dié van die falankse. Identifikasie en die kant bepaling van handbeentjies is dus skaars en so word hulle van baie forensiese gevalle uitgesluit. Forensiese antropologiese studies sluit ook die bepaling van demografiese eienskappe soos liggamslengte en geslag in. Die skedel, bekken, femur en tibia van die menslike skedel is akkurate aanduiders by die bepaling van statuur en geslag. Handbeentjies word dikwels van sulke studies uitgelaat omdat hulle relatief klein en swak bewaar is. Die doel van hierdie studie was ten eerste die voorsiening van gedetailleerde morfologiese beskrywings van metakarpale en falankse van die menslike hand, tweedens, die ontwikkeling van omskakelingsformules vir statuur met aanwending van die handbeentjies en derdens, die ontwikkeling van diskriminante funksie formules waarby die handbeentjies gebruik kan word om die geslag van n onbekende individue te bepaal. Die studie het bestaan uit 200 stelle handbeentjies van Suid-Afrikaanse individu. Die resultate dui aan dat daar benige landmerke is om elke handbeen te identifiseer en te onderskei tussen links en regs. Die onderskeie beentjies van die menslike hand se lengte kan gebruik word om dié van n langbeen te bepaal, wat op sy beurt gebruik kan word om statuur te bedien. Akkuraatheid van geslagsbepaling deur middel van handbeentjies is hoog vir mans en vrouens. Gemiddelde betroubaarheid was meer as 80%. Ontleding van menslike handbeentjies kan dus n waardevolle bydrae lewer by die ondersoek van skelette van onbekende individue. xviii

19 ACKNOWLEDGEMENTS This subject was a difficult and rare one, especially the descriptive aspect. Nevertheless, I have found it most heartening and it has taken great pains to bring out this work with the help of the Almighty. My first encounter with Prof M Yasar İşcan and the many discussions we had concerning the problems facing forensic scientists in identifying and siding hand bones gave me the strong incentive to do a PhD on the skeleton of the hand. The statistical analysis was a great task indeed and would not have been possible without the assistance of Prof MY İşcan s and Dr SAS Olorunju from the Biostatistics Unit at the University of Pretoria and Prof M Steyn s motivation. I am grateful to Prof M Steyn who encouraged me to pursue the questions as a PhD student and gave me guidance and support throughout. I am most grateful to Prof JH Meiring for allowing me access to the dissection cadavers and Pretoria Bone Collection. For the technical assistance, I would like to thank Mr Erik Marakalla, who assisted in the maceration of the skeletons and to Mrs Louisa Hutten who made the gruelling task of photographing each hand bone appear so easy. I thank her for the patience and skill she exercised in this task. I am grateful to Mrs Marinda Pretorius for all the line diagrams, to Mrs AM Du Plessis, Mrs Santie Swarts and Marius Loots for their advice in formatting the entire document. Thanks to the library staff, especially Mrs Janice de Wee and Mrs Kabelo Nzima, who were most helpful with obtaining all the references I needed. My gratitude is extended to the students who volunteered to read the descriptive chapters. A word of thanks to Leona Vorster, Susan Gaigulo, and Chantal Van Roey for assisting with refworks and editing of the references. My thanks also goes to the Anatomy staff and the many friends who always passed a word of encouragement throughout this period. There are a number of people that I have not mentioned but that I hold dear to my heart for their words of wisdom. This thesis would not have been possible without the help, patience, encouragement from my family especially my mother, Rita (Ruwayda) Angela Marrian. To my nieces, Naseemah and xix

20 Nazeerah Mia, and my sisters Naeema Mia and Bedelia Anastasia Padiachy, there will be more free time now to spend with you. It is said that there are two kinds of knowledge, the knowledge of religions and the knowledge of the body. I pray that I have fulfilled both of these in an attempt to better understand the design of each bone of the hand with the wisdom given to me by the Almighty Insha Allaah Ameen. xx