How much tension must be developed by the erector spinae with a moment arm of 6 cm from the L5-S1 joint center to maintain the body in a lifting position with segment moment arms as specified? (Segment weights are approximated for a 600-N (135-lb) person.) Known: Segment Weight 50 N Moment Arm 22 cm 12 cm Head Trunk 250 N Arms 65 N 25 cm Box 100 N 42 cm 6 cm Fm Note: the sum of the torques acting at any point is zero when the body is in a static position

How much tension must be developed by the erector spinae with a moment arm of 6 cm from the L5-S1 joint center to maintain the body in a lifting position with segment moment arms as specified? (Segment weights are approximated for a 600-N (135-lb) person.) Known: Segment Weight 50 N Moment Arm 22 cm 12 cm Head Trunk 250 N Arms 65 N 25 cm Box 100 N 42 cm 6 cm Fm Note: the sum of the torques acting at any point is zero when the body is in a static position

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter38: The Musculoskeletal System

Section: Chapter Questions

Problem 34CTQ: Describe the joints and motions involved in taking a step forward if a person is initially standing...

See similar textbooks

Similar questions

When running on the balls of one’s feet, what muscle resists dorsiflexion of the talocrural joint and stores elastic energy?
Consider the importance of forearm position (pronation/supination) on the influence of the muscle providing force during flexion of the elbow. 1. Please outline which radioulnar/forearm position would be best to isolate each of the three main elbow flexors AND 2. provide a brief explanation of why hand position makes a difference.
An isometric exercise is one in which the joint angle does not change during the application of muscle force. For instance, you can join your hands together, pushing down with one hand and pushing up with the other. In each arm, the muscles that provide the force are connected to the bones of the arm by tendons. If you increase the forces but keep the angles the same, the muscles will still contract. Explain how this is possible.
During this silent period what structures are likely to be producing trunk extension torque? Is this torque being generated actively or passively?
Describe the bony articulations and movementsspecific to shoulder joint rotation during the accel-eration phase of the throwing motion and how anathlete can work toward increasing the velocity ofthe throw. What factors affect the velocity of thethrow?
Determine the kind of flexibility exercises thatwould be indicated for a patient with carpal tun-nel syndrome, and explain in detail how theyshould be performed.
Locate and list two different pairs of muscles that act as on the body as agonist/antagonist. (That is, in each pair, one muscle will produce a movement, such as flexion, that the other muscle will undo, and produce extension; abduction/adduction, etc. are other ways that muscle produce opposite actions on the same part of the body).Name two muscles that act as “fixators.” (What are fixators?) What joint or joints are they helping to stabilize?Why is the biceps brachii called a “bicep,” while the triceps brachii is called a “triceps?”What is the difference between a muscle with “longus” as part of its name and a muscle with “brevis” as a part of its name?
Why can you lift a larger load when your elbow is slightly flexed and your biceps muscle is at an intermediate length than you can when your elbow is fully extended?
List two sport skills that involve movements moreclearly seen from the front or rear. List the pri-mary movements that occur in the transverse tar-sal/subtalar joint, hip, spine, glenohumeral joint,and wrist. In which plane are these movements predominantly occurring? What axis of rotation isprimarily involved?
Which joint movement (angular velocity) is occurring during stance phase of stair ascer
Which of these increases force production? 1. Increasing the velocity of the concentric contraction 2. Increasing the velocity of the eccentric contraction 3. Increasing strength of neural stimulation 4. Holding your breath during contraction 5. Increasing frequency of neural stimulation 6. Decreasing the velocity of the concentric contraction 7. Starting the contraction with the joint in full extension 8. Decreasing the velocity of the eccentric contraction
During a Physical Education class, you ask your students to perform a standing vertical jump. Identify the type of muscle contraction involved in the jump and describe the movement patterns of the concentric and eccentric phases. Outline the agonists, antagonists and synergist muscles, which contribute to maximum jump height. Identify the major lower body joints and joint movements, which contribute to the concentric phase of the jump.