Complete the following problems from Chapter 7 of your book.
Calculate your answer to two decimal
places, and use correct units. You must show ALL of your work for full credit.
Introductory Problems:
1. Construct a chart listing all muscles, with their origins and insertions, crossing the glenohumeral joint
according to whether they are superior, inferior, anterior, or posterior to the joint center. Note that
some muscles may fall into more than one category (for these muscles, you do not need to re-write the
origins and insertions). Identify the action or actions performed by muscles in each of the four
categories.
2. A) Construct a chart listing all muscles, with their origins and insertions, crossing the elbow joint
according to whether they are superior, inferior, anterior, or posterior to the joint center. Note that
some muscles may fall into more than one category (for these muscles, you do not need to re-write the
origins and insertions). Identify the action or actions performed by muscles in each of the four
categories.
3. Construct a chart listing all muscles, with their origins and insertions, crossing the wrist joint according
to whether they are superior, inferior, anterior, or posterior to the joint center. Note that some muscles
may fall into more than one category (for these muscles, you do not need to re-write the origins and
insertions). Identify the action or actions performed by muscles in each of the four categories.
6. Explain how the use of an overhand as compared to an underhand grip affects an individual's ability to
perform a pull-up.
8. Using the diagram in Sample Problem 7.1 as a model, calculate the total tension required in the
deltoid with a moment arm of 3cm from the shoulder, attaching at an angle of 25 degrees, given the
following weights and moment arms for the upper arm (u), forearm (f), and hand (h) segments:
wtu=19N, wtf=11N, wth=4N, du=12cm, df=40cm, dh=64cm.
10. (Use Sample problem 7.2 as a model with this information) How much force must be produced by
the brachioradialis and biceps (Fm) to maintain the 15N forearm and hand, and a 10kg bowling ball, held
in the position shown in Problem 7.2, given moment arms of 5cm for the muscles, 15cm for the
forearm/hand weight, and 35cm for the bowling ball? What is the magnitude of the joint reaction force?
Additional Problems:
1. Identify the sequence of movements that occur at the scauplothoracic, shoulder, elbow, and wrist
joints during the performance of an overhand throw.
2. Which muscles are most likely to serve as agonists to produce the movements identified in your
answer to Problem 1?
6. Discuss the importance of the rotator cuff muscles as stabilizers of the glenohumeral joint and movers
of the humerus. In your answer, be sure to name the rotator cuff muscles.
