1. Pelvis Biomechanics
Session 15

2. Essays
Citations
Grammar
Outside resources

3. Objectives
To deduce the motions that each ligament in the pelvic girdle prevents, to analyze the structure and function relationship with regard to the pelvic girdle, and to analyze the concept of stability vs flexibility with regard to the pelvic girdle.

4. Sacroiliac Joint - Ligaments
Primary:
Anterior Sacroiliac
Interosseus
Short and long posterior sacroiliac
Secondary:
Sacrotuberous
Sacrospinous

5. Sacroiliac Joint - Motions
Anterior Tilt and Posterior Tilt
Nutation (sacral flexion) and Counternutation (sacral extension)
Stability vs. Mobility

7. Case Study Patient complains of LBP near left SI joint
L leg longer than R
Gymnast with R leg dominance
Which ASIS would be anteriorly rotated?
Why would it also be medially rotated?

8. Your patient has significant posterior tilt in his pelvis but when palpating, you notice his sacrum is nutated. What ligament would be most stretched?
Posterior Sacroiliac
Anterior Sacroiliac
Sacrospinous
None of these would be stretched

9. Tibiofemoral Joint – Bony Variations
Genu Vara and Genu Valga
Will affect the amount of force transferred between the two femoral condyles – one side will carry more weight and be damaged faster
Hip and ankle issues may also result

10. An elderly patient with noticeable genu varus walks into your clinic
An elderly patient with noticeable genu varus walks into your clinic. Which side of the knee is he more likely to have osteoarthritis in?
Medial
Lateral

11. Tibiofemoral Joint – Menisci
Both:
Have an anterior and posterior horn to hold it to the Tibia
Are attached to the capsule and Tibia on the external edge by the coronary ligaments
Coronary ligaments are loose and allow menisci to pivot
Are held together anteriorly by the transverse ligament
Blood supply near external border, avascular near internal border
Aneural except near the horns
Function as shock absorbers!
Medial Meniscus
C shape
External border is attached to the MCL and capsule
Lateral Meniscus
O shape
External border attached to the capsule and Popliteus Muscle
Posterior border is attached to the femur by the Posterior Meniscofemoral Ligament

12. Tibiofemoral Joint – Ligaments
LAMP
Lateral Collateral Ligament (Fibular Collateral)
Dense and strong
Medial Collateral Ligament (Tibial Collateral)
Less dense, two parts, weaker
Anterior Cruciate Ligament (ACL)
Anterior Tibia -> Posterior Femur
Posterior Cruciate Ligament (PCL)
Posterior Tibia -> Anterior Femur
Anterior Lateral Ligament (ALL)
Lateral epicondyle -> Gerdy’s tubercle
Tibiofemoral Joint – Ligaments

13. Which ligament(s) are you testing by pulling a patient’s tibia anteriorly relative to the femur?
PCL
ACL
LCL
ALL