Gait deviations in Transtibial prosthesis users

Gait deviations in transtibial amputations involve altered biomechanics and asymmetries. Research highlights that spatiotemporal gait parameters are affected, with reduced propulsive force, knee extension moment, and increased knee abduction moment in the amputated leg. Additionally, individuals with transtibial amputations exhibit shorter stance times, longer swing times, and larger step lengths compared to able-bodied individuals. These deviations can lead to asymmetrical loads, potentially causing issues like osteoarthritis or lower back pain. Furthermore, gait asymmetry in transtibial amputees is associated with poor functional outcomes, impacting performance-based physical function tests like the Timed Up and Go, the 10-Meter Walk Test, and the 6-Minute Walk Test. Understanding these gait abnormalities is crucial for tailored interventions and prosthetic design to improve outcomes for individuals with transtibial amputations.

1. Gait deviations in Transtibial prosthesis users Dr. joe antony Physical medicine and rehabilitation Kgmu

2. Contents Dr. Joe Antony 2 Basics of gait Ranchos los amigos gait terminology Kinematics Kinetics and muscle action Deviations in Initial contact loading response Mid stance Terminal stance Preswing Swing phase

3. Ranchos los amigos gait terminology Stance Phase Starting point End point Initial contact Foot comes in contact with ground Loading response Initial contact C/l foot leaves ground Mid stance C/l foot leaves ground I/l heel leave the ground Terminal stance I/l heel leave the ground C/l initial contact Preswing C/l initial contact I/l feet leaves ground 3 Dr. Joe Antony

4. Ranchos los amigos gait terminology Swing Phase Starting point End point Initial swing Foot leaving the ground I/l foot in alignment with C/l Ankle Mid swing I/l foot in alignment with C/l Ankle I/l tibia become vertical Terminal swing I/l tibia become vertical Initial contact 4 Dr. Joe Antony

5. Sagittal plane kinematics 5 Dr. Joe Antony

6. Ground reaction force and its effect 6 Dr. Joe Antony

7. Kinetics and muscle action 7 Dr. Joe Antony Initial contact and loading response Mid stance progression

8. 8 Dr. Joe Antony Terminal stance Preswing

9. Initial contact Initial contact with the heel Normal toe out angle is kept at 5-10 degree, heel-to-toe progression through lateral border Knee maintained in 5-10 flexion Stride length equal to that of the sound side 9 Dr. Joe Antony

10. Deviations in initial contact Initial contact with forefoot Knee fully extended Knee excessively flexed Unequal stride length 10 Dr. Joe Antony

11. Initial contact with forefoot Causes Solution Excessive plantar flexion of prosthetic feet Realignment of feet Restricted ROM of extension ( knee flexion contracture) Exercises to improve ROM, adjust the socket to accommodate the contracture 11 Dr. Joe Antony

12. Knee fully extended Possible causes Solution Faulty suspension, does not maintain knee in 5-10 degrees flexion Correct suspension system Insufficient pre flexion of socket Increase flexion attitude of the socket Foot too anterior Slide foot posteriorly 12 Dr. Joe Antony

13. Knee excessively flexed (greater than 10degrees) Possible causes Solution Faulty suspension (maintain knee in greater than 10 degree flexion) Correct suspension system Flexion contracture Evaluate ROM then decide Accommodate if less than 20 degree Stretch the hamstrings Surgical correction of deformity 13 Dr. Joe Antony

14. Unequal stride length Shorter stride on sound side Shorter stride on prosthetic limb Lack of confidence in prosthesis- in new users Flexion deformity of knee joint Increased gait training Management of knee flexion deformity 14 Dr. Joe Antony

15. Loading response Smooth knee flexion to approximately 20 degrees Approximately 3/8” heel compression No piston action 15 Dr. Joe Antony

16. Deviations in loading response Abrupt knee flexion Knee remains extended Piston action 16 Dr. Joe Antony

17. Abrupt knee flexion Causes Solution Weak quadriceps Strengthening Foot too posterior Slide foot anteriorly Knee flexion deformity/socket too flexed/foot is dorsiflexed Reduce socket flexion Heel on shoe is too high Select correct shoe or change foot Cushion heel too firm (no compression) Evaluate amount of heel compression( may be less than 3/8”) and adjust Shoe does not allow heel cushion to compress sufficiently. Modify the shoe 17 Dr. Joe Antony

18. Knee remains extended Causes Solutions Foot is too anterior Move foot posteriorly Insufficient socket flexion Increase socket flexion SACH heel too soft ( more than 3/8) Select firmer heel Heel on shoe too low Add heel Excessive use of knee extensors Gait training 18 Dr. Joe Antony

19. Piston Action ( >6mm ) Causes Solution Suspension too loose Correct suspension Not enough prosthetic socks Add Socks Not enough support under medial tibial flare or patellar tendon Add appropriate pads or make new socket 19 Dr. Joe Antony

20. Mid stance Pylon vertical Socket displaced laterally by about ½” (duplicates varum moment at mid stance) 2-4” between medial sides of feet (as swinging foot passes stance foot) No excessive lateral trunk bending 20 Dr. Joe Antony

21. Deviations in mid stance Pylon leans medially Pylon leans laterally ½” varus moment not apparent Varus moment excessive Less than two inches between feet at mid stance Greater than four inches between feet at mid stance Lateral trunk bending to prosthetic side 21 Dr. Joe Antony

22. Gait deviation Causes Solutions Pylon leans medially Too much adduction in the socket Reduce socket adduction Foot may be outset Adjust the position of foot Pylon leans laterally Not enough adduction in the socket Increase socket adduction Foot may ne inset Adjust the position of foot 22 Dr. Joe Antony

23. Deviations Causes Solutions ½” varus moment not apparent (for some patients who cannot control varus force, this is desirable) Foot relatively outset Inset foot Varus moment excessive ( more than ½” never desirable) Foot too inset Reduce foot inset Socket ML too wide (Lateral gapping) Reduce socket ML 23 Dr. Joe Antony

24. Gait deviations Problems Solutions Less than 2 inches between feet at mid stance Foot Inset (narrow base gait) Reduce foot inset Greater than four inches between feet at midstance Foot too outset Reduce foot outset 24 Dr. Joe Antony

25. Lateral trunk bending to prosthetic side Causes Solutions Prosthesis too short Evaluate and correct length Residual limb pain ( patient leans laterally to reduce the torque) Evaluate for residual limb pain Foot too outset Reduce foot outset 25 Dr. Joe Antony

26. Terminal Stance Heel off should occur smoothly and effortlessly prior to initial contact on the sound side Immediately after heel off the knee should to flex in preparation for toe off 26 Dr. Joe Antony

27. Deviations in terminal stance Heel-off occurs early Heel-off is delayed 27 Dr. Joe Antony

28. Early heel off Causes Solutions Excessive posterior position of the foot ( short toe lever arm) Move the foot anteriorly Foot excessively dorsiflexed ( socket in too much flexion) Reduce foot dorsiflexion 28 Dr. Joe Antony

29. Delayed heel off 29 Dr. Joe Antony Causes Solutions Excessive anterior position of the foot ( long toe lever arm) Move the foot posterior Foot plantar flexed ( insufficient socket flexion) foot dorsiflexion

30. Pre swing Smooth transfer of body weight to the sound side Socket remains adequately suspended as swing phase is initiated 30 Dr. Joe Antony

31. Deviations in pre swing Drop off Socket drops away from the residual limb 31 Dr. Joe Antony

32. Drop off- Patient appears to fall too quickly to the sound side Causes Solutions Foot too posterior Slide foot posteriorly Foot too dorsiflexed (Excessive socket flexion) Reduce foot dorsiflexion 32 Dr. Joe Antony

33. Socket drops off- Gaps between socket and stump Casuses Solution Suspension is too loose Readjust the suspension Not enough prosthetic socks Add socks 33 Dr. Joe Antony

34. Swing phase During initial swing the heel of the foot should accelerate smoothly with no tendency to “whip” medially or laterally During mid swing the foot should swing through without touching the floor. The patient should not have to exert extra effort to assure clearance 34 Dr. Joe Antony

35. Deviations in swing phase Foot whips medially or laterally during initial swing Prosthetic foot touches the floor during mid swing 35 Dr. Joe Antony

36. Foot whips medially or laterally during initial swing Causes Solution Cuff suspension not aligned evenly Reposition of suspension attachment Prosthetic socket is rotated medially or laterally with respect to line of progression Readjust the socket alignment 36 Dr. Joe Antony

37. Prosthetic foot touches the floor during midswing Causes Solution Prosthesis is too long Shorten prosthesis Suspension is too loose Tighten the suspension Limited knee flexion – By socket or suspension system Evaluate the degree flexion with prosthesis and eliminate limitations Muscle weakness or lack of gait training Strengthening of the knee flexors and gait training 37 Dr. Joe Antony

38. 38 Dr. Joe Antony References Braddoms textbook of PMR 21 st edition Orthotics and Prosthotics in rehabilitation, Kevin K chui , 4 th edition Atlas of orthosis and assistive devices , 4 th edition, AAOS Thank you