1. Muscles and Joints 1 1

2. What are Muscles? Muscle  Fascicle Muscle fiber  Myofibril
Units are bundled together with various connective tissues
Myofibril consists of bands of actin and myosin filaments. 2 2

3. Muscles and Movement
On a cellular level:
ACh released by the axon ending signals a release of Ca2+
Ca2+ removes complex over the actin fibril.
Myosin head attaches to actin groove and contracts
ATP is hydrolyzed to move myosin head back to the starting position. 3 3

4. But muscles do not produce systemic motion by themselves!
Muscles and Movement
On a systemic level:
Most muscles work in muscle pairs:
Contracting  Agonist
“Relaxing”  Antagonist
Contraction
Relaxation
But muscles do not produce systemic motion by themselves! 4 4

5. Joints Consist of: Bone* Cartilage* Muscle* Ligaments* Tendons*
Synovium*
Nerves
Glands
Blood Vessels 5 5

6. Joints Synovial Joints: Majority of the joints in your body
Contain a synovial cavity or sheath between the contact points
Synovial cavity with fluid allows joints to glide across each other 6 6

7. Joints Motion Classification: Hinge Ball and Socket Pivot Ellipsoidal
And many more
Each joint has a certain Range of Motion (ROM) associated with it. 7 7

8. Knee 8 8

9. Extension and Flexion:
Knee
Hinge Joint
Synovial Joint
ROM:
Extension and Flexion:
-5 to 143 degrees (women)
-6 to 140 degrees (men)
Studies of the range of knee motion show that -
93 degrees is required for rising from a seated position
106 degrees is required for shoelace tying
135 degrees is required to take a bath 9 9

10. Lateral Collateral Ligament (LCL)
Knee Ligaments
Lateral Collateral Ligament (LCL)
Located:
Outer (or Lateral) side of the knee.
Function:
Mediolateral Stability 10 10

11. Medial Collateral Ligament (MCL)
Knee Ligaments
Medial Collateral Ligament (MCL)
Located:
Inner (or Medial) side of the knee.
Function:
Mediolateral Stability
Covers major glands and nerves of the knee 11 11

12. Anterior Cruciate Ligament (ACL)
Knee Ligaments
Anterior Cruciate Ligament (ACL)
Located:
Inside the knee joint, under the patella, near the front (anterior)
Function:
Resists anterior translation and medial rotation of the tibia 12 12

13. Posterior Cruciate Ligament (PCL)
Knee Ligaments
Posterior Cruciate Ligament (PCL)
Located:
Inside the knee joint, under the patella, near the back (posterior)
Function:
Prevent the femur from sliding anterior to the tibia and tibia from displacing posterior to the femur 13 13

14. Chicken Leg
The chicken’s knee is analogous to the human knee!! Let’s look for those ligaments! 14 14

15. Measuring the Effects of Injury and Illness15 15

16. Injury and Illness Stress/Strain related: Fracture: Arthritis: 16 16

17. Current treatment Drug Therapy Reattachment Partial Joint Replacement
Total Joint Replacement 17 17

18. Ability to Align Growing Fibrils
Hopes for the Future
Stem Cell Therapy
Ability to Align Growing Fibrils
Degradable Metal Scaffolding 18 18

19. Knee 19 19

20. Extension and Flexion:
Knee (Revisited)
Hinge Joint
Synovial Joint
ROM:
Extension and Flexion:
-5 to 143 degrees (women)
-6 to 140 degrees (men)
Studies of the range of knee motion show that -
93 degrees is required for rising from a seated position
106 degrees is required for shoelace tying
135 degrees is required to take a bath
A loss of anything more than 3 degrees of motion can lead to serious problems and pain. 20 20

21. The Screw Home Mechanism
Why???
The Screw Home Mechanism 21 21

22. Any questions?