Question
Sagittal plane hip, knee, and ankle coordinates were digitized (shown in the figure) from the right lower extremity of a person walking. Provide the equations, show all the steps, and provide correct units with the answers. Provide answer to 2 decimal places unless stated otherwise. USE ONLY the formulas provided please! PLEASE ALSO DON'T FORGET TO DRAW ALL DIAGRAMS. Answer parts a-c.
![FORMULAS AND INFORMATION TO USE:
- 360 degrees = 2pi radian or 6.284
- 1 radian = 360 degrees / 6.284
- 1 radian =57.3 degrees
-(x) angle in degrees/57.3 degrees radian = (x) radians
-(x) radians * 57.3 degrees/ radians = (x) degrees
- Absolute [segment] angles: theta = tan^-1 (opp/adj) = y2-y1/x2-x1
=
proximal y distal y divided by proximal x - distal ✗
- If a negative angle is clockwise from the left horizontal, to convert counter-clockwise angle from the right, add
180 degrees.
oppy2-Y1
adi = X2-X1
(X2,Y2)
opp
Ꮎ
(X1.V1)
adj
- To calculate relative angles, use the formulas:
Ohip = thigh-trunk
Oknee =
Othigh- Oshank
Oankle = foot-shank - 90°
tane shank
Kneey Ankley
Kneex Anklex
- Angular velocity is also
απ
Δω
Δι
i
At
- Angular acceleration (a)
=
wfinal-winital (units is Tad
tfinal-tinital
•
Angle ([A]in radians)
=
•
Arc length (As)
Radius of rotation (r)
Arc length(As) = Radius of rotation(r) x angle ([A]in radians)
•
LINEAR AND ANGULAR DISPLACEMENTS As = r AO
•
Tangential velocity formula is ✓=r*w (answer should be in m/s)
* AO, THETA, R, A AND or w (OMEGA) need to be converted to radians.
AS1
* Linear velocity
=
At
Τ1 Αθ
At
•
Tangential (VT) velocity depends on
.
Distance from radius of rotation (r)
Angular velocity (w)
EXAMPLLE OF TANGENTIAL VELOCITY WITH A FOOT:
foot tangential velocity (VTfoot) depends
on
thigh
Whip
Wknee shank
wwww
Change in
position
⚫Thigh length (high) and hip
angular velocity (whip)
•Shank length (shank) and knee
angular velocity (knee)
• Vr foot = ("thigh x Whip) + (Tshank xwknee)
• To increase the foot tangential
velocity, increase angular velocity
of thigh and shank rotation
Vfoot
- Angular displacement is (A0) =
RADIANS.)
Ofinal
Oinitial (NEVER EXCEEDS 360 DEGREES OR 2 PI
Initial
position
Final
position
- Angular speed = angular distance/time (units is rad/s).
- Angular velocity (w)
final - initial
=
(units is rad/s)
time final - time initial](https://content.bartleby.com/qna-images/question/14055f04-58ff-4c00-af23-66e4ceb29afb/37398bab-5497-4cc3-b7f0-20a9ffa5d5de/2c6rq3m_thumbnail.png)
Transcribed Image Text:FORMULAS AND INFORMATION TO USE:
- 360 degrees = 2pi radian or 6.284
- 1 radian = 360 degrees / 6.284
- 1 radian =57.3 degrees
-(x) angle in degrees/57.3 degrees radian = (x) radians
-(x) radians * 57.3 degrees/ radians = (x) degrees
- Absolute [segment] angles: theta = tan^-1 (opp/adj) = y2-y1/x2-x1
=
proximal y distal y divided by proximal x - distal ✗
- If a negative angle is clockwise from the left horizontal, to convert counter-clockwise angle from the right, add
180 degrees.
oppy2-Y1
adi = X2-X1
(X2,Y2)
opp
Ꮎ
(X1.V1)
adj
- To calculate relative angles, use the formulas:
Ohip = thigh-trunk
Oknee =
Othigh- Oshank
Oankle = foot-shank - 90°
tane shank
Kneey Ankley
Kneex Anklex
- Angular velocity is also
απ
Δω
Δι
i
At
- Angular acceleration (a)
=
wfinal-winital (units is Tad
tfinal-tinital
•
Angle ([A]in radians)
=
•
Arc length (As)
Radius of rotation (r)
Arc length(As) = Radius of rotation(r) x angle ([A]in radians)
•
LINEAR AND ANGULAR DISPLACEMENTS As = r AO
•
Tangential velocity formula is ✓=r*w (answer should be in m/s)
* AO, THETA, R, A AND or w (OMEGA) need to be converted to radians.
AS1
* Linear velocity
=
At
Τ1 Αθ
At
•
Tangential (VT) velocity depends on
.
Distance from radius of rotation (r)
Angular velocity (w)
EXAMPLLE OF TANGENTIAL VELOCITY WITH A FOOT:
foot tangential velocity (VTfoot) depends
on
thigh
Whip
Wknee shank
wwww
Change in
position
⚫Thigh length (high) and hip
angular velocity (whip)
•Shank length (shank) and knee
angular velocity (knee)
• Vr foot = ("thigh x Whip) + (Tshank xwknee)
• To increase the foot tangential
velocity, increase angular velocity
of thigh and shank rotation
Vfoot
- Angular displacement is (A0) =
RADIANS.)
Ofinal
Oinitial (NEVER EXCEEDS 360 DEGREES OR 2 PI
Initial
position
Final
position
- Angular speed = angular distance/time (units is rad/s).
- Angular velocity (w)
final - initial
=
(units is rad/s)
time final - time initial

Transcribed Image Text:Hip (1.32, 0.75)
Knee (1.62, 0.51)
Thigh
0Knee.
Ꮎ .
Shank
Calculate the following:
Ankle (1.35, 0.23)
a. Thigh segment angle (0
Thigh)
Draw a diagram here. Write the equations and show all your work.
b. Shank segment angle (leg)
Draw a diagram here. Write the equations and show all your work.
c. Knee joint angle (knee)
Draw a diagram here. Write the equations and show all your work.
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