1. Select a subject who is dressed in loose fitting shorts. Place this subject so that he/she performs an active extension of the femur at the hip from a neutral or 0o starting position. The movement must be accomplished without gravity resisting or assisting the movement. (Hint, you may have to assist the subject for balance.) Do the same activity for abduction of the humerus at the shoulder, flexion of the forearm at the elbow, and flexion of the tibia at the knee. In each case have the subject complete a full range of motion. How did you decide that gravity was not resisting or assisting the motions?

In what plane did each of the motions take place?

2. Have your subject sit on the edge of the table with his/her feet dangling. Have them flex the right forearm at the elbow to about 120o. Grasp the wrist of the flexed arm with your right hand and ask the subject to keep the elbow flexed and their left hand. Now, gradually pull on the right wrist in an attempt to straighten the elbow. Pull until you obtain a reaction from the subject. What reaction did you obtain?

Now, place your left hand in front of the subject’s right shoulder, your palm to his shoulder, and push against the shoulder as you pull with your right hand. Pull hard with your right hand, but do not allow the shoulder to come forward.

3. Select two subjects, each with the shoulders exposed. One subject should have a large frame and well-defined shoulder girdle musculature. The other should be slightly built with relatively small shoulder girdle musculature. Seat the subjects on low stools. Stand behind the larger subject and ask him/her to abduct the humerus at the shoulder to 90o bilaterally. Place your hand just above the elbow and have the subject resist while you push down vigorously. How much resistance can you apply? Can you break the contraction?

 Now, resist the slightly built subject in the same way. Could you break that contraction?

Answer the following questions:

a. Is either subject considered abnormal?

b. Were you able to apply maximal resistance to each subject?

c. Define maximal resistance.

4. a. On the slightly built subject, with the humerus abducted 90o at the shoulder apply your downward force just above the elbow, but at an acute angle rather than perpendicular to the humerus; have most of your force directed laterally rather than downward. Compare the force you needed to apply in this exercise with the force you used in item 3. Was there a difference in the amount of force you had to apply to break the contraction? Why?

b. With the same subject, repeat the process but place your resisting hand on the humerus just distal to the shoulder joint rather than close to the elbow. Apply your resistance perpendicular to the humerus. Compare the force you exerted to break the abduction contraction this time to the force you used in items 3 and in 4.a, above.

5. Select a subject who has well-developed shoulder musculature and normal shoulder structure. Ask the subject to assume the position described in item 3. Tell the subject that you will be applying maximum pressure and ask the subject to fix the shoulders as well as he can. Place your hands at the elbows and apply downward pressure firmly and quickly. You will see the arms go down slightly, even though the subject is strong and was theoretically prepared for the resistance. Repeat the procedure and build your resistance slowly. The arms will not go down.

How do these findings relate to the technique of applying resistance in a manual muscle-testing?

 1. Select a subject with his/her back exposed. Stabilize the right scapula with your right hand on the lateral border so that it does not move laterally during abduction or flexion of the humerus at the shoulder. Ask the subject to flex the humerus at the shoulder. Again, make sure the scapula does not move. Now, repeat the motions and allow the scapula to participate in each of the movements freely.

Now, press your hand on the flat of the scapula so that the inferior angle of the scapula maintains close contact with the chest wall. Ask the subject to rotate the humerus medially at the shoulder with the scapula stabilized and then with it free to move.

Describe the difference in range of motion available in all of these situations.

1. Using an articulated skeleton, examine the relationship of the greater tuberosity and the acromion during abduction without rotation of the humerus at the shoulder. What occurs with this relationship if the humerus is medially rotated during abduction?

Laterally rotated?

2. Place your subject supine on the table with her shoulder at the edge of the table. Stand on the side of the table near that shoulder and support the upper extremity by holding the subject’s hand. Try to get your subject completely relaxed so you can move the extremity passively with no participation from the subject’s musculature. Be sure to have the extremity into complete abduction. Be sure to move slowly and continue to obtain complete relaxation from the subject. At the beginning of the movement, you should see the anterior surface of the brachium uppermost. At the end of the range of motion you should see the medial surface of the brachium uppermost. (Uppermost means facing upward toward the ceiling.)

Describe the motion of the humerus at the glenohumeral joint that you observed.

Considering that there was no muscle contraction on the part of the subject and that you did not try to create any motion other than abduction, explain why this motion occurred. Hint: examine the configuration of the ligamentous fibers of the articular capsule. 

3. Have your subject perform active extension of the humerus at the shoulder in a fashion that will allow the triceps to assist with the movement with the greatest active tension possible through the largest range of motion possible. What principle was being demonstrated?

4. Your partner has lost function of cranial nerve XI. Muscle test a back/neck muscle directly affected, and then the movements secondarily affected. 

5. What joint is primarily affected by the costoclavicular ligament? What are the effects on that joint of a torn costoclavicular ligament?