TRAINING LAB – SKELETAL REMAINS: DETERMINING A VICTIM’S … · 2013-09-01 · 1 meter stick/group – to measure the lengths of bones 1 “Height Measuring” Station – students

TRAINING LAB – SKELETAL REMAINS: DETERMINING A VICTIM’S HEIGHT

NAME___________________________________________ Background: As a Forensic Anthropologist you have been trained to identify skeletal remains – but what can the bones you identify tell you about the victim? One important piece of information a bone can help you uncover is the victim’s approximate height. Knowing the victim’s height can be an important first step in discovering the victim’s identity. 1. You will be trained to analyze skeletal remains to determine a victim’s height. Procedures:

Part 1 – Measuring Your Own Bones To Determine Your Height 1. Use a meter stick and accurately measure the length of your Femur to the nearest 0.5 centimeter. Record your measurement in Table 1. 2. Repeat Step #1 and measure the length of your Tibia, Humerus, and Ulna to the nearest 0.5 centimeter. Record these measurements in Table 1. 3. Finally, measure your height to the nearest 0.5 centimeter. Record your height in Table 1. 4. Anthropologists have measured the heights and bone lengths of many humans to see if there is a relationship between bone length and height. After analyzing a large mass of data they discovered a distinct relationship between bones and height. Formulas were derived from this data that will allow a Forensic Anthropologist to measure the length of a single bone from a person and calculate that person’s approximate height (the height is usually accurate to 1 or 2 inches). These important formulas can be found in Table 2. 5. Use your Femur length measurement (from Table 1) and the correct Femur formula (from Table 2) to calculate your approximate height in centimeters. Record your Calculated Height in Table 1. 6. Repeat Step #5 to calculate your approximate height using your Tibia, Humerus, and Ulna length measurements. Check carefully to make sure you are using the correct formula for each calculation. Record each Calculated Height in Table 1. 7. Convert all your Table 1 Centimeter Heights (Actual and Calculated) into the more familiar Feet and Inches. Follow these simple steps: Step #1 – Use the following Formula to convert centimeters into inches. Round your answers to the nearest inch. Step #2 – Convert total Inches to Feet and Inches (48 inches = 4 feet, 60 inches = 5 feet, 72 inches = 6 feet). EXAMPLE: 65 inches = 5 feet 5 inches Record all Feet and Inch heights in Table 1.

Height in Inches = 2.54 Centimeters per Inch

Height in Centimeters

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Part 2 – Measuring Skeletal Remains To Determine A Victim’s Height

1. Your Supervisor has a collection of skeletal remains from various crime scenes that have been sent to you for analysis. Studies of the skulls found with these bones helped investigators determine each victim’s race and sex. They need your help to determine each victim’s approximate height. Below is the information that is known about each of the bones.

Measure the total lengths of each of the bones as accurately as possible. Determine the Approximate Height (in Feet and Inches) of each of the victims. Record your results in Table 3. Part 3 – Using Height Calculations To Analyze A Crime Scene

1. A shallow grave, filled with the skeletal remains of what is believed to be at least two people, was recently discovered in a nearby county. Only a mix of arm and leg bones were found in the grave, which has made it difficult for the sheriff’s department to determine exactly how many victims were buried. The sheriff’s department carefully measured each bone’s length (bone length is the only information they have been able to gather from the skeletal remains). This bone length data just arrived in our lab today. They would like for you to use height calculations to help determine the number of victims in the grave. 2. The bone length data can be found in Table 4 – “Bone Evidence Summary Sheet”. Complete the “Bone Evidence Summary Sheet” so we can send the results back to the Sheriff’s Department.

Bone Name Race Sex

Ulna Caucasian Male

Femur African-American Female

Fibula Unknown Unknown

Radius Asian Male

Tibia African-American Male

Humerus Caucasian Female

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DATA TABLES – SKELETAL REMAINS: DETERMINING A VICTIM’S HEIGHT

NAME___________________________________________

Bone NameBone Length

(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Femur

Tibia

Humerus

Ulna

My Actual Height (cm)

My Actual Height (inches)

My Actual Height (ft/inches)

Table 1 – My bone lengths and calculated height


(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Ulna

Femur

Fibula

Radius

Tibia

Humerus

Table 3 – Estimated heights calculated from skeletal remains

359

How many different victims do you believe were buried in the mass grave? List the Estimated Height of each victim below. Next to each victim’s height write the number of bones from the grave that you believe belong to that victim.


(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Ulna 24cm

Femur 45cm

Fibula 34cm

Humerus 32cm

Humerus 30cm

Radius 24.5cm

Femur 41cm

Tibia 36.5cm

Fibula 39cm

Radius 24.5cm

Tibia 33.5cm

Radius 26.5cm

Femur 48cm

Humerus 36cm

Table 4 – Bone Evidence Summary Sheet

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Table 2 – Formulas used to calculate Estimated Height (cm) from Bone Length (all bone measurements MUST be made in Centimeters)

Bone Name Race Male Female

Caucasian (2.89 x length) + 78.10cm (3.36 x length) + 57.97cm

African-American (2.88 x length) + 75.48cm (3.08 x length) + 64.67cm

Asian (2.68 x length) + 83.19cm use unknown formula

Unknown




Unknown




Unknown




Unknown




Unknown




Unknown

Ulna

Femur

Tibia

Fibula

(4.62 x length) + 19.00cm

(3.78 x length) + 74.7cm

(4.61 x length) + 46.83cm

(2.71 x length) + 45.86cm

(3.29 x length) + 47.34cm

(3.59 x length) + 36.31cm

Humerus

Radius

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QUESTIONS – SKELETAL REMAINS: DETERMINING A VICTIM’S HEIGHT

NAME________________________________

1. On the average, how far off (in inches) were your calculated heights from your actual height? 2. Which of your bone(s) gave you the most accurate estimation of your actual height? 3. Which of your bone(s) gave you the least accurate estimation of your actual height? 4. The formulas that you used for calculating your estimated height are based on measurements from adult bones. How could this affect your calculated height results? 5. Why would knowing the sex of a bone allow you to make a more accurate estimation of the victim’s height? 6. You measure a bone and calculate the height of the victim is 5 feet 11 inches. Why is it correct to say that this is the victim’s Estimated Height?

362

TEACHER NOTES Lab/Activity: Training Lab – Skeletal Remains: Determining A Victim’s

Height Equipment To Prepare: 1 meter stick/group – to measure the lengths of bones 1 “Height Measuring” Station – students will need to measure their correct height (in cm)

during the Training Lab. This process can be sped up by taping two meter sticks to a a wall (one from the floor up and the second continuing onward from the end of the first). Students can stand in front of the two meter sticks and a third meter stick (or similar) can be placed flat on the student’s head to help determine their correct height.

1 calculator/group – to calculate heights 1 each of the following bones placed in a tray or a central location for student access (these can be a random assortment of right or left bones from different disarticulated sets). However, if you have female disarticulated bones you could place female bones for the Femur and Humerus – although male bones will work fine for all. The bones should not be labeled in any way. 1 Humerus (female) 1 Femur (female) 1 Radius 1 Tibia 1 Ulna 1 Fibula These bones will be used for Part 2 of the Training Lab. All the students in the class can use these same bones SIX bones (it doesn’t take long to measure the length of a

bone – so their isn’t much wait time). You should also measure the lengths of the SIX bones you use, calculate approximate

heights (according to the instructions in Part 2 of the Training Lab), and record these results in the supplied KEY (found after these Teacher Notes).

Comments/Problems: This Training Lab usually takes 1 day to complete if students measure and calculate very quickly. Otherwise, it will spill over to a second day. The formulas used in the Training Lab came from Bass, W.M. (1987), Human Osteology: A Laboratory and Field Manual. Students sometimes find great variability when calculating their own heights from bone lengths. This is often due to inaccurate measurements (it is harder to measure the length of a bone when it is inside your body), the fact that the bone formulas are based on adult bones, and the fact that the calculations give an approximate height only.

Typical Results: Keys to the Training Lab Tables and Questions follow these Teacher Notes.

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DATA TABLES – SKELETAL REMAINS: DETERMINING A VICTIM’S HEIGHT

NAME___________________________________________


(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Femur

Tibia

Humerus

Ulna

My Actual Height (cm)

My Actual Height (inches)

My Actual Height (ft/inches)

Table 1 – My bone lengths and calculated height


(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Ulna

Femur

Fibula

Radius

Tibia

Humerus

Table 3 – Estimated heights calculated from skeletal remains

KEY

ANSWERS WILL VARY FOR EACH STUDENT

MEASURE THE BONES YOU USE, CALCULATE HEIGHTS,

AND RECORD HERE.

364

How many different victims do you believe were buried in the mass grave? List the Estimated Height of each victim below. Next to each victim’s height write the number of bones from the grave that you believe belong to that victim.

Table 4 – Bone Evidence Summary Sheet


(cm)

Calculated

Height

(cm)

Calculated

Height

(inches)

Calculated

Height

(ft./inches)

Ulna 24cm 157.47 62 5' 2"

Femur 45cm 167.81 66 5' 6"

Fibula 34cm 158.37 62 5' 2"

Humerus 32cm 166.84 66 5' 6"

Humerus 30cm 157.6 62 5' 2"

Radius 24.5cm 167.31 66 5' 6"

Femur 41cm 156.97 62 5' 2"

Tibia 36.5cm 167.43 66 5' 6"

Fibula 39cm 176.32 69 5' 9"

Radius 24.5cm 167.31 66 5' 6"

Tibia 33.5cm 157.56 62 5' 2"

Radius 26.5cm 174.87 69 5' 9"

Femur 48cm 175.94 69 5' 9"

Humerus 36cm 185.32 73 6' 1"

4

Victim #1 Height = 5’ 2” 5 bones Victim #2 Height = 5’ 6” 5 bones Victim #3 Height = 5’ 9” 3 bones Victim #4 Height = 6’ 1” 1 bone

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QUESTIONS – SKELETAL REMAINS: DETERMINING A VICTIM’S HEIGHT

NAME________________________________

1. On the average, how far off (in inches) were your calculated heights from your actual height? 2. Which of your bone(s) gave you the most accurate estimation of your actual height? 3. Which of your bone(s) gave you the least accurate estimation of your actual height? 4. The formulas that you used for calculating your estimated height are based on measurements from adult bones. How could this affect your calculated height results? 5. Why would knowing the sex of a bone allow you to make a more accurate estimation of the victim’s height? 6. You measure a bone and calculate the height of the victim is 5 feet 11 inches. Why is it correct to say that this is the victim’s Estimated Height?

KEY

ANSWERS WILL VARY – SOME WILL BE VERY CLOSE, WHILE OTHERS WILL VARY GREATLY

ANSWERS WILL VARY

ANSWERS WILL VARY

STUDENTS ARE STILL GROWING, THEREFORE, IT IS MORE LIKELY THAT CALCULATED HEIGHTS WOULD BE INCORRECT AND SHOW MORE VARIATION.

FEMALE BONES ARE TYPICALLY SHORTER THAN MALE BONES. CALCULATIONS WOULD BE MORE ACCURATE IF THE FORMULA IS BASED ON FEMALE BONES ONLY – RATHER THAN USING A FORMULA THAT AVERAGES BOTH MALE AND FEMALE BONE LENGTHS TOGETHER.

THESE FORMULAS ARE BASED ON AVERAGE BONE LENGTHS. SOME PEOPLE MAY BE SOMEWHAT TALLER THAN THE CALCULATED HEIGHT, WHILE OTHERS MAY BE SOMEWHAT SHORTER THAN THE CALCULATED HEIGHT. CALCULATED HEIGHTS SHOULD ALWAYS BE REPORTED AS “ESTIMATED” HEIGHT.

366

TRAINING LAB – SKELETAL REMAINS: DETERMINING A VICTIM’S SEX

NAME___________________________________________ Background: Humans look different from each other on the outside – each of us with our own external characteristics. We can easily recognize males and females, and one individual from another, because we have had years of experience observing these external differences. Forensic Anthropologists have also discovered male and female differences in a part of the body we’re NOT used to observing – the male and female skeletal system. Not only can a victim’s approximate height be determined by skeletal remains, but the sex of the victim can also be determined with a fair degree of accuracy – especially after you have had years of practice. 1. You will be trained to analyze skeletal remains to determine if a victim is a male or a female. Procedures:

There are several different bones that can help determine if skeletal remains came from a male or female victim. In this Training Lab you will work with the bones that are most commonly used by Forensic Anthropologists for sex determination. You do NOT have to begin with Part 1 for this Training Lab. If other groups are using the Part 1 skulls you should move on to another section of the lab and come back to Part 1 later.

Part 1 – Using The Skull And Mandible For Sex Determination 1. Your Supervisor has set out skulls for you to observe. You may be asked to observe one or two different numbered skulls (your Supervisor will tell you how many different skulls you should observe). 2. Bring one of the skulls back to your lab station. Please DO NOT point to parts of the skull with your pen or pencil and mark on the skull. 3. Write the number of the skull you are observing in Table 5 – “Sex Determination Of Skeletal Remains - SKULL” (the number can be found on the top of the skull). 4. Carefully observe the characteristics of your skull using Table 1 – “Characteristics of Male and Female Skulls” as your guide (Table 1 can be found on the next page). This Table describes Male and Female characteristics that are generally visible on skulls. Labeled diagrams of Male and Female skulls/mandibles have also been included to assist you. 5. Record each of your skull’s characteristics in Table 5. Record your observation in the “Male” column if you observed a Male characteristic, in the “Female” column if you observed a Female characteristic, and in the “Can’t Determine” column if the observed characteristic seemed to be between Male and Female. 6. Look at all your observations and decide if you have a Male or Female skull (do you have more characteristics recorded in the Male or Female column)? Record your final result in Table 5. 7. Repeat Steps #3 - #6 for a second skull (if supplied by your Supervisor). 8. Check the KEY found in the front of the room to see if your conclusions are correct!

367

AREA OF

SKULLMALE FEMALE

ForeheadFrom A Side View - Appears to be

sloping backward

From A Side View - Appears to be more

straight up and down

Orbit

ShapeUsually more square-shaped Usually more round-shaped

Upper Edge

Of OrbitMore of a rounded, less sharp edge More of a sharp edge

Mastoid

ProcessLarger Smaller

External Occipital

Protuberance Larger Small or missing

Mandible

AngleCloser to a 90

o Angle Angle much larger than 90

o

Chin Shape More of a square shape More of a rounded, pointy shape

Table 1 - Characteristics of Male and Female Skulls

More square orbit shape

Upper orbit has more of a rounded edge

Chin shape is more square

More rounded orbit shape

Upper orbit has more of a

sharp edge

Chin shape is more rounded/pointy

Sloping forehead

Mastoid process larger

External Occipital

Protuberance larger

Mandible Angle closer to 900

Straight forehead

Mastoid process smaller

External Occipital

Protuberance small or missing

Mandible Angle much larger than 900

MALE SKULL/MANDIBLE FEMALE SKULL/MANDIBLE

368

Part 2 – Using The Pelvis (Coxal Bones, Sacrum, Coccyx) For Sex

Determination 1. The next bone to observe is the Pelvis. You may be asked to observe more than one numbered Pelvis (your Supervisor will tell you how many you should observe). 2. Bring a Pelvis back to your lab station. Please DO NOT point to parts of the Pelvis with your pen or pencil and make marks on the bone. 3. Write the number of the Pelvis you are observing in Table 6 – “Sex Determination Of Skeletal Remains - PELVIS”. 4. Carefully observe the characteristics of your Pelvis using Table 2 – “Characteristics of The Male and Female Pelvis” as your guide (Table 2 can be found below). Labeled diagrams of the Male and Female Pelvis have also been included to assist you. 5. Record each of your Pelvis’s characteristics in Table 6. Record your observation in the “Male” column if you observed a Male characteristic, in the “Female” column if you observed a Female characteristic, and in the “Can’t Determine” column if the observed characteristic seemed to be between Male and Female. 6. Look at all your observations and decide if you have a Male or Female Pelvis (do you have more characteristics recorded in the Male or Female column)? Record your final result in Table 6. 7. Repeat Steps #3 - #6 for a second Pelvis (if supplied by your Supervisor). 8. Check the KEY found in the front of the room to see if your conclusions are correct!

AREA OF

PELVISMALE FEMALE

Front View Of The

Subpubic AngleLess than a 90

o angle

Like a "V" shape

90o angle or larger angle

Like an "L" shape

Top View Of The

Pelvic Cavity Shape

The space you see inside is more

"heart" shaped and small

The space you see inside is more

oval/circular in shape and larger

Sacrum Shape

Sacrum is longer and thinner.

The Sacrum and coccyx are tilted

toward the inside of the Pelvic

Cavity and are easily visible from

a top view.

Sacrum is shorter and wider. The

Sacrum and coccyx are tilted

backward away from the Pelvic

Cavity and are not very visible

from a top view.

Pubic Bone Width

(in mm) From The

Center Of The Pubis

Symphysis To The

Obterator Foramen

(the large hole)

Measure with a ruler (mm). The

Pubic Bone Width at this location

is less than 30mm.

Measure with a ruler (mm). The

Pubic Bone Width at this location

is greater than 35mm.

**PUBIS SYMPHYSIS** where the two coxal bones meet in the front (ventral)

Table 2 – Characteristics of the Male and Female Pelvis

369

IF YOU ONLY HAVE ONE COXAL BONE 1. You can still accurately estimate what the subpubic angle would be (less than or greater than 900). 2. You can still measure the width of the Pubic Bone from the center of the Pubis Symphysis to the Obturator Foramen.

#1 – Subpubic Angle

#2 – width

of the Pubic

Bone here

Top view of pelvic cavity – space is

small and “heart” shaped

Sacrum is tilted inward with

coccyx pointing into the space

Top view of pelvic cavity – space is large and oval or circular shaped

Sacrum is tilted backward with coccyx barely

pointing into the space

MALE PELVIS

Sacrum longer and thinner

Front view of subpubic angle is less than 900

“V-shaped”

Measure the width of the pubic bone here (in mm). If it is less than 30mm = Male,

greater than 35mm = Female

FEMALE PELVIS

Front view of subpubic angle is greater than 900

“L-shaped”

Sacrum shorter and wider

370

Part 3 – Using The Humerus For Sex Determination 1. The next bone to observe is the Humerus. You may be asked to observe more than one numbered Humerus (your Supervisor will tell you how many you should observe). 2. Bring a Humerus back to your lab station. Please DO NOT point to parts of the Humerus with your pen or pencil and make marks on the bone. 3. Write the number of the Humerus you are observing in Table 7 – “Sex Determination Of Skeletal Remains - HUMERUS”. 4. Carefully observe the characteristics of your Humerus using Table 3 – “Characteristics of the Male and Female Humerus” as your guide (Table 3 can be found below). You will be taking measurements of the Humerus (in millimeters) to determine sex. You can either place a millimeter ruler behind the Humerus when taking measurements, or you can use a caliper (for a more accurate measurement) if one is available. 5. Record each of your Humerus’s characteristics in Table 7. Record your observation in the “Male” column if you observed a Male characteristic, in the “Female” column if you observed a Female characteristic, and in the “Can’t Determine” column if the observed characteristic seemed to be between Male and Female. 6. Look at all your observations and decide if you have a Male or Female Humerus (do you have more characteristics recorded in the Male or Female column)? Record your final result in Table 7. 7. Repeat Steps #3 - #6 for a second Humerus (if supplied by your Supervisor). 8. Check the KEY found in the front of the room to see if your conclusions are correct!

Width Between Epicondyles

Dorsal View Of The Humerus Transverse

Diameter of Head

Vertical Diameter of

Head

MEASUREMENTS

OF THE HUMERUSMALE

COULD BE MALE

OR FEMALEFEMALE

Transverse Diameter

Of The Head

greater than

47 mm43 to 47 mm

less than

43 mm

Vertical Diameter

Of The Headcloser to 48.8 mm 45.8 mm closer to 42.7 mm

Width Between

Epicondylescloser to 63.9 mm 60.4 mm closer to 56.8 mm

Total Length Of The

Humeruscloser to 339.0 mm 322.5 mm closer to 305.9 mm

Table 3 – Characteristics of the Male and Female Humerus

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TRAINING LAB – SKELETAL REMAINS: DETERMINING A VICTIM’S … · 2013-09-01 · 1 meter stick/group – to measure the lengths of bones 1 “Height Measuring” Station – students