Basic Biomechanics
7th Edition
ISBN: 9780073522760
Author: Susan J Hall
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Question
Chapter 13, Problem 4IP
Summary Introduction
To determine: The force produced by the biceps.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
With the shoulder flexed at 30°, the moment arm of the deltoid muscle is 2.0 cm. Solve
for the force exerted by the deltoid muscle at the glenohumeral joint give the following
assumptions:
The deltoid is the only active muscle at the glenohumeral joint
The weight of the humerus is 48 N.
The center of gravity of the humerus is located 30 cm from the shoulder center of
rotation
STATIC EQUILIBRIUM EQUATIONS
CONSIDERING ONLY THE DELTOID MUSCLE
Fo
MA =
18 Cn
COR
B=55".
0-30°
RaF 30 cm
FG = 24 N
If your biceps brachii muscle attaches to your forearm 2 inches below your elbow, the distance from the elbow to the palm of your hand is 18 inches, and you lift a 20 pound weight, how much pull must your muscle exert to achieve elbow flexion? If your biceps brachii muscle attaches to your forearm 2 inches below your elbow, the distance from the elbow to the palm of your hand is 18 inches, and you lift a 20 pound weight, how much pull must your muscle exert to achieve elbow flexion?
hhh
ney:
Load (L) = 5 kgs
= Effort
E = Fulcrum
Weight of forearm = 1.8 kgs
L = Load
Biceps brachii
muscle
Distance of load from elbow joint = 35 cm
%3D
Effort (E) = contraction
of biceps brachii
Distance of center of mass of forearm from elbow = 17 cm
Distance of tendon from elbow = 4 cm
A) Draw the free-body diagram to represent the forces and moments
Load (L) = weight of
object plus forearm
B) Write the torque equation for static equilibrium
Fulcrum (F) = elbow joint
Chapter 13 Solutions
Basic Biomechanics
Ch. 13 - Why does a force directed through an axis of...Ch. 13 - Why does the orientation of a force acting on a...Ch. 13 - A 23-kg boy sits 1.5 m from the axis of rotation...Ch. 13 - Prob. 4IPCh. 13 - Two people push on opposite sides of a swinging...Ch. 13 - Prob. 6IPCh. 13 - Prob. 7IPCh. 13 - Prob. 8IPCh. 13 - A 10-kg block sits motionless on a table in spite...Ch. 13 - Prob. 10IP
Ch. 13 - A 35-N hand and forearm are held at a 45 angle to...Ch. 13 - A hand exerts a force of 90 N on a scale at 32 cm...Ch. 13 - A patient rehabilitating a knee injury performs...Ch. 13 - A worker leans over and picks up a 90-N box at a...Ch. 13 - A man carries a 3 m, 32-N board over his shoulder....Ch. 13 - A therapist applies a lateral force of 80 N to the...Ch. 13 - Tendon forces Ta and Tb are exerted on the...
Knowledge Booster
Similar questions
- Explain the answer biomechanicallyarrow_forwardThe adjacent diagram displays the joint reaction force between the acetabulum and femoral head for the right leg during single leg stance. Also shown are the abductor muscle force (AMF), the weight of the body above the level of the stance hip (W) and their corresponding moment arms with respect to the joint centre (D and D1). If the right leg weighs 1/6 of total body weight, the ratio of D1 to D is 2.4, and AMF is angled at 30 degrees relative to the vertical, calculate the: Abductor muscle force (2 marks). Hip joint reaction force (2 marks). Express both answers as multiples of total body weightarrow_forwardA) Describe the difference between strength and power during a squat. Provide a quantitative example that illustrates the difference. B) During a squat, the weight you have on your shoulders has a certain amount of gravitational potential energy. As you squat down and come to a stop at the bottom of the squat, some of that energy is lost. Where does it go?arrow_forward
- < The three main forces that act on the patella are shown on the diagram of the knee joint below. These forces are the quadriceps muscle force (FQ), the patella ligament force (FPL), and the patellofemoral joint reaction force (FPF). The angles a and ẞ are with respect to a line that is perpendicular to FPF. Assuming a = 15°, ẞ = 20°, and FQ = 3725 N, use equations for static equilibrium to calculate (a) FPL, and (b) FPF. (Hint: To solve this problem consider using a coordinate system that is aligned with the principal axes of the patella instead of the usual vertical and horizontal axes). (c) Many people assume FQ and FPL are always equal in magnitude but this is only true under certain circumstances. Under what conditions are FQ and FPL equal in magnitude? Fo FPF FP B GriffithUNIVERSITY Queensland Australiaarrow_forward2. a) Label the system provided below, including the reference frame, moment arms and vector forces with the information provided. Internal moment arm = 4cm +0.04m External moment arm relative to the segment weight = 25cm 0.25m External moment arm relative to the load weight = 45cm 40.45m Segment weight = 50 N Load weight = 100 N Lower leg segment angle relative to horizontal plane = 45° Quadriceps tendon angle = 45° Axis of rotation MF SW LW 2b) Using the figure in 2a., calculate the external torque of the system relative to the normal component of segment and load weights listed above. 2c) Calculate the amount of both the tangential component of the muscle force and the muscle force itself required to keep this system in a state of static equilibrium.arrow_forwardIf the muscle fiber is stretched to 150% of muscle length and thentechnically stimulated, what would be the total force measured?arrow_forward
- Total compressive knee forces range between O 1-2 %BW O 2-4 %BW 3-5 %BW 0.5-1.5 %BWarrow_forwardIf an individual does training with only the right knee extensor muscles, it is common to see increase in strength in knee extension force for the right leg and an increase in strength in the knee extension force of the left leg (although the increase in force is typically not to the same extent as the force increase in the right leg) a.) True b.) Falsearrow_forwardTwo lifter's knees are of interest at a specific moment in their lifts. In both lifts, the knee extensor torque is 100 Nm, requiring quadriceps tendon/patella ligament forces of 1000 N (about 220 Ibs). Despite equivalent knee torques and quadriceps forces, patellofemoral joint forces are higher on the knees of lifter A. Briefly explain why. Edit View Insert Format Tools Table 12pt v Paragraph v BIUAarrow_forward
- GIVE 3 EXERCISE THAT CAN BE CONSIDERED AS A LOCOMOTOR MOVEMENT WITH FLEXION AND EXTENSION MOVEMENT AND WHYarrow_forward5 of 10 Which of the following exercises would be an example of a Stabilization-Focused exercise for the shoulders? Standing cable row Bench press Single-leg dumbell overhead press shoulder press machine Next ▶arrow_forwardGIVE 3 EXERCISES THAT CAN BE CONSIDERED AS A LOCOMOTOR MOVEMENT WITH LATERAL ROTATION AND MEDIAL ROTATION MOVEMENT AND WHY?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Lifetime Physical Fitness & WellnessHealth & NutritionISBN:9781337677509Author:HOEGERPublisher:Cengage
Lifetime Physical Fitness & Wellness
Health & Nutrition
ISBN:9781337677509
Author:HOEGER
Publisher:Cengage