1. Gait (3) Sagittal Plane Analysis Lecture Notes

2. Example To Make Things Clear  If during gait knee flexion is necessary, & a flexion moment is acting on the knee: 1.The flexion is the desirable motion 2.If control is necessary, eccentric muscle contraction of knee extensors is required to control flexion  If during gait knee extension is necessary, & a flexion moment is acting on the knee: 1.The extension is the desirable motion 2.A concentric contraction of knee extensors is necessary to oppose the flexion moment & produce knee extension

3. Gait Stance Phase In The Period of Heel Strike to Foot Flat

4. Rule No. 1 If we want CONTROL  eccentric contraction in the antagonist muscles

5. What’s Happening to The Hip Joint Flexion The line of gravity is anterior The moment created is a flexion moment The desired motion is flexion We have a flexion moment, & the desired motion is ALSO flexion  we need control Eccentric contraction happens at the hip extensors (Gluteus Maximus) to control the amount of hip flexion

6. What’s Happening to The Knee Joint Flexion The line of gravity is posterior The moment created is a flexion moment The desired motion is flexion We have a flexion moment, & the desired motion is ALSO flexion  we need control Eccentric contraction happens at the knee extensors (quadriceps) to control the amount of knee flexion

7. What’s Happening to The Ankle Joint Planterflexion The line of gravity is posterior The moment created is a planterflexion moment The desired motion is planterflexion We have a planterflexion moment, & the desired motion is ALSO planterflexion  we need control Eccentric contraction happens at the Tibialis Anterior to control the amount of ankle planterflexion

8. Gait Stance Phase In The Period of Foot Flat to Midstance

9. What’s Happening to The Hip Joint Flexion The line of gravity is anterior The moment created is a flexion moment The desired motion is extension We have a flexion moment, & the desired motion is extension Concentric contraction happens at the hip extensors (Gluteus Maximus) to do extension of the hip joint

10. What’s Happening to The Knee Joint Flexion The line of gravity is posterior The moment created is a flexion moment The desired motion is extension We have a flexion moment, & the desired motion is extension Concentric contraction happens at the knee extensors (quadriceps) to do extension of the knee joint

11. What’s Happening to The Ankle Joint The line of gravity moves anteriorly The moment created is a dorsiflexion moment The desired motion is dorsiflexion We have a dorsiflexion moment, & the desired motion is dorsiflexion  we need control Eccentric contraction happens at the planterflexors (gastrocnemius) to control the amount of ankle dorsiflexion

12. Rule No. 2 If the moment & the desired motion are the same  we need control  eccentric contraction in the antagonist muscle If the moment & the desired motion are the different  concentric contraction in the agonist muscles

13. Gait Stance Phase In The Period of Midstance to Heel Off

14. What’s Happening to The Hip Joint The line of gravity is posterior The moment created is a extension moment The desired motion is extension We have an extension moment, & the desired motion is Also extension  we need control Eccentric contraction happens at the hip flexors (iliopsoas) to control the amount of hip extentiom

15. What’s Happening to The Knee Joint Nothing Happens !

16. What’s Happening to The Ankle Joint The line of gravity moves anteriorly The moment created is a dorsiflexion moment The desired motion is planterflexion We have a dorsiflexion moment, & the desired motion is planterflexion Concentric contraction happens at the planterflexors (gastrocnemius) to do ankle planterflexion

17. Gait Stance Phase In The Period of Heel Off to Toe Off

18. What’s Happening to The Hip Joint The line of gravity is posterior The moment created is a extension moment The desired motion is flexion We have an extension moment, & the desired motion is flexion  we need control Concentric contraction happens at the hip flexors (iliopsoas) to do hip flexion

19. What’s Happening to The Knee Joint The line of gravity is posterior The moment created is a flexion moment The desired motion is flexion We have a flexion moment, & the desired motion is flexion  we need control Eccentric contraction happens at the knee extensors (quadriceps) to do extension of the knee joint

20. What’s Happening to The Ankle Joint The line of gravity moves anteriorly The moment created is a dorsiflexion moment The desired motion is planterflexion We have a dorsiflexion moment, & the desired motion is planterflexion Concentric contraction happens at the planterflexors (gastrocnemius) to do ankle planterflexion

21. Gait Swing Phase Acceleration to Midswing

22. Rule No. 3 When the muscle works against gravity it works concentrically

23. Rule No. 4 In Swing Phase There Is No Ground Force Reaction Because There is No Contact With The Floor

24. What’s Happening to The Hip Joint The motion is flexion Concentric contraction happens at the hip flexors (iliopsoas) to do hip flexion Eccentric cotraction happens at the hip extensors (Gluteus Maximus)  to control the amount of hip flexion

25. What’s Happening to The Knee Joint The motion is flexion Concentric contraction happens at the knee flexors (hamstrings) to do knee flexion Eccentric cotraction happens at the knee extensors (quadriceps)  to control the amount of knee flexion

26. What’s Happening to The Ankle Joint The motion is dorsiflexion Concentric contraction happens at the ankle dorsiflexors (tibialis anterior) to do ankle dorsiflexion Eccentric contraction happens at the ankle planterflexors (Gasrocnemius)  to control the amount of ankle dorsiflexion

27. Gait Swing Phase Midswing to Deceleration

28. What’s Happening to The Hip Joint The hip remain at 30° flextion Eccentric contraction happens at the hip extensors (Gluteus Maximus) to control the movement

29. What’s Happening to The Knee Joint The motion is extension Concentric contraction happens at the knee extensors (quadriceps)  to control the amount of knee extension Eccentric contraction happens at the knee flexors (hamstrings) to do knee extension

30. What’s Happening to The Ankle Joint Ankle remains in neutral Controlled by tibialis anterior, extensor digitorum longus, extensor hallicus longus

31. Good Luck