Transfemoral Prosthesis Gait Deviations.pptx

Gait deviations in transfemoral prosthetics can result from various factors related to both the patient and the prosthesis. Common patient-related causes include muscle weakness, contractures, pain, decreased confidence in the prosthesis, or habitual behaviors. Prosthetic causes often involve malalignment or poor-fitting sockets1.

Transfemoral amputees typically exhibit a more asymmetric gait compared to transtibial amputees. The level of amputation and the type of prosthesis significantly influence the gait pattern, affecting both performance and adaptation. For instance, the selection of suspension type in the prosthesis can impact stability and, consequently, gait deviation2.

It’s important to assess and address these deviations as they can lead to other complications such as increased energy expenditure during walking, joint stress, and discomfort. Rehabilitation efforts should focus on correcting these deviations through proper prosthetic fit, alignment, and training to improve the patient’s gait and overall mobility

1. Transfemoral Prosthesis Gait Deviations -Rushikesh Rajgude BPO, MGMIUDPO

2. Introduction While assessing amputee gait it is important to be aware of normal gait and how normal gait in the amputee is affected. Furthermore, there may be deviations which an amputee will adopt to compensate for the prosthesis, muscle weakness or tightening, lack of balance and fear. These deviations create an altered gait pattern and it is important that these are recognized, as rehabilitation of the gait will need to encompass corrections of these deviations

3. 1. Instability of the prosthetic knee Description: The prosthetic knee tends to flex during the prosthetic stance phase, creating a danger of falling. When to observe: During stance phase How to observe: From the side

4. Causes: 1. The knee joint may be too close to, or anterior to the Trochanter-Knee-Ankle (TKA) line. 2. The socket may have been aligned in too little flexion. 3. There may be too much plantarflexion resistance (prosthetic heel or plantarflexion bumper are too hard) , causing the knee to flex at heel strike. 4. If the foot is set in dorsiflexion or the foot is too small, leading to incomplete knee control. 5. The amputee’s hip extensors may be weak, and they are unable to provide adequate force to control the knee. 6. The amputee may have a severe hip flexion contracture, which has not been compensated for, causing instability.

5. 2. Medial/Lateral Whip Description: A medial whip occurs at toe-off when the heel moves to the inside (medially) as the knee begins to bend. A lateral whip occurs at toe-off when the heel moves to the outside (laterally) as the knee begins to bend. When to observe: At or just after toe-off How to observe: From behind the amputee

6. Causes: 1. Medial whip is caused when the knee axis has too much external rotation. 2. Lateral whip is caused when the knee axis has too much internal rotation. 3. The socket may be too tight or have not enough space to accommodate muscles. Pressure from contracting muscles then causes the prosthesis to rotate around its long axis. 4. The toe break may not be set at the correct angle to the line of progression. 5. The stump may have weak, loose musculature, in which tissues rotate freely around the femur.

7. 3. Circumduction Description: The prosthesis is swung in a half-circle away from the body. When to observe: Throughout swing phase How to observe: From behind the amputee

8. Causes: Circumduction is often a patient response to a prosthesis that is too long, or behaving in a way that makes it too long. This causes the amputee to swing the prosthesis out to the side to clear the foot (such as:) 1. Manual knee lock, too much friction, or a tight extension aid may prevent the knee from bending. 2. Inadequate suspension may allow the prosthesis to slip off the stump (piston action). 3. The socket is too small/tight. The ischial tuberosity is above the ischial seat. 4. The foot is set in plantarflexion. 5. The prosthesis is actually too long. Other reasons for circumduction can be: 6. The amputee uses little or no knee flexion because of insecurity or fear. 7. Habit 8. Discomfort in the perineal area.

9. 4. Vaulting: Description: The amputee’s center of gravity moves up and down excessively The entire body is raised by excessive plantarflexion of the sound foot. You can observe that the normal foot is raised onto the toes while walking. When to observe: During sound leg stance phase How to observe: From behind the amputee or from the side

10. Causes: 1. Vaulting is a patient response to a prosthesis which is too long, or behaving in a way that makes it too long, (such as) The amputee vaults so that the foot will clear the ground in mid swing • Inadequate suspension allows the prosthesis to slip off the stump (piston action). • Manual knee lock, too much friction, or a tight extension aid may prevent the knee from bending. • The socket is too small/tight. The ischial tuberosity is above the ischial seat. • The foot is set in plantarflexion. • The amputee uses little or no knee flexion because of insecurity or fear. • The prosthesis is actually too long. • Habit – the patient may have walked in this manner for a long time.

11. CONTD….. 2. There is not enough control of heel rise in early swing phase (friction / pneumatic / hydraulic resistance). In normal gait, maximum elevation of the body occurs when the supporting limb is in the middle of stance phase and the other limb swings alongside it. When there is not enough control of heel rise in early swing phase the shank takes a longer time to swing forward. Because of this time lag, the body is no longer at maximum elevation as the prosthetic foot is at its lowest point in swing through. The prosthetic foot would fail to clear the ground unless the amputee gained additional time and clearance by vaulting.

12. 5. Abducted Gait: Description: The width of the walking base is much greater than the normal range of 50-100 mm. There is usually exaggerated lateral displacement of the pelvis and lateral bending of the trunk. You will observe that the prosthesis is always put out to the side while walking. When to observe: During the period of double support How to observe: From behind the patient

13. Causes: 1. The prosthesis behaves like it is too long. The amputee walks with an abducted gait so that the prosthesis will clear the ground during swing phase. This could be due to one of the causes 2. The shank is aligned in a valgus position in relation to the thigh section. 3. There is pain or discomfort in the crotch area. The discomfort may be caused by factors such as skin infection, adductor roll, or pressure from the brim of the medial socket wall. The amputee tries to gain relief by abducting the prosthesis, thus moving the medial brim away from the painful area. 4. The mechanical hip joint may be set so that the socket and stump are brought into abduction. 5. The abductors of the hip may be contracted. 6. The amputee may feel insecure, and may compensate by widening the walking base. listed under Circumduction.

14. 6. Lumbar Lordosis Description: The normal convexity of the lumbar area is exaggerated when the prosthesis is in stance phase. When to observe: Throughout stance phase How to observe: From the side

15. Causes: 1. There is a flexion contracture of the hip. A flexion contracture aggravates the tendency of the pelvis to tilt anteriorly because the shortened hip flexor muscles pull on the pelvis and lumbar spine when the hip moves into extension. The amputee throws his or her shoulders back to compensate for the forward tilt of the pelvis, and to maintain stability. 2. The socket has been aligned in too little flexion. 3. There is not enough support from the brim of the anterior socket wall. This allows the pelvis to rotate anteriorly and pulls the lumbar spine into lordosis. 4. The patient’s hip extensors are weak. The extensors help to restrain the tendency of the pelvis to tilt forward. When this restraining force is lost, the resulting forward tilt of the pelvis and compensatory backward bending of the trunk causes increased lordosis. In addition, the amputee may roll the pelvis forward to assist the weak extensors to control stability of the prosthetic knee.

16. CONTD…. 5. The patient’s abdominal muscles are weak. The abdominal muscles usually restrain the tendency of the pelvis to tilt forward. When the abdominal muscles are weak, some of this restraint is lost and the amputee will show increased lordosis. 6. Weight-bearing on the ischium may be painful. The amputee may roll the pelvis forward to relieve pressure on the ischium.

17. 7. Lateral bending of the trunk Description: The patient leans the body towards the prosthetic side when the prosthesis is in stance phase. This movement shifts the patient’s center of gravity towards the prosthesis. When to observe: From just after heel strike to mid-stance How to observe: From behind the patient

18. 1. The prosthesis is too short. 2. The lateral wall of the socket does not provide enough support. If there is not enough support to block lateral movement of the femur, the pelvis will tend to drop on the sound side when the prosthesis is in stance phase. To correct this, the amputee leans towards the prosthetic side. 3. The socket is abducted. This alignment fault reduces the effectiveness of the hip abductors in stabilizing the pelvis. The pelvis will tend to drop on the sound side, and the amputee will try to correct this by leaning towards the prosthetic side. 4. The lateral distal part of the stump is painful or uncomfortable and the amputee tries to relieve pressure on it by leaning towards the prosthetic side. 5. The amputee’s abductors are weak. As above, lateral bending corrects the tendency towards pelvic drop on the sound side. 6. Lateral bending of the trunk usually occurs when an amputee walks with an abducted gait. The same factors that cause abducted gait may also cause lateral bending. Causes:

19. 7. Rotation of the foot on heel strike Description: As the heel contacts the ground, the foot rotates laterally, sometimes with a vibratory motion. When to observe: At heel strike How to observe: From in front of the patient

20. Causes: 1. The plantarflexion bumper or heel cushion is too hard. 2. If the patient has a new suction socket, foot rotation may be due to poor control of the socket by the stump. 3. The patient may be correcting his or her gait after a lateral whip

21. 8. Terminal swing Impact Description: The prosthetic shank comes to a sudden stop with strong impact as the knee goes into extension. You may hear a noise when the prosthesis is fully extended. When to observe: At the end of swing phase How to observe: From the side

22. Causes: 1. There is not enough friction / pneumatic / hydraulic control on the prosthetic knee. 2. There is too much tension on the extension aid. 3. The amputee’s fear of knee flexion causes him/her to sharply extend the stump as the knee approaches full extension. This movement snaps the shank forward into full extension and then “digs” the heel into the ground.

23. 8. Drop-off Description: At the end of stance phase, as the body moves forward over the prosthesis there is a downward movement of the trunk. When to observe: At the end of stance phase How to observe: From the side

24. Causes: 1. There may not be enough restriction of dorsiflexion of the prosthetic foot. (The dorsi-flexion bumper is too soft, the foot is too small, the foot is broken) 2. The keel of the SACH foot may be too short, or the toe break of a conventional foot may be too far posterior. 3. The socket may have been placed too far anterior in relation to the foot.

25. 9. Uneven heel rise Description: The prosthetic heel rises higher than the sound heel, OR the prosthetic heel shows a smaller rise than the sound heel. When to observe: During initial swing phase How to observe: From the side

26. Causes: Too much heel rise may be caused by: 1. Not enough control (friction / pneumatic / hydraulic) on the prosthetic knee. 2. No extension aid, or not enough tension in the extension aid. 3. The patient forcefully flexing the stump to ensure that the prosthetic shank will be fully extended at heel strike. Too little heel rise may be caused by: 1. Too much control (friction / pneumatic/ hydraulic) on the prosthetic knee. 2. The extension aid being too tight. 3. Fear and insecurity, as the amputee walks with little or no knee flexion. 4. Manual knee lock.

27. 10. Uneven timing Description: The steps are of unequal duration. There is usually a very short stance phase on the prosthetic side. When to observe: Throughout the gait cycle How to observe: From the side

28. Causes: 1. The socket may not fit properly. To avoid pain, the amputee may try to shorten the stance phase on the prosthetic side. 2. Alignment stability may be a factor, if the knee flexes too easily. 3. The amputee may not have developed good balance. 4. The patient may have weak muscles. 5. Fear and insecurity may contribute to this problem.

29. References: Atlas of Prosthesis Biomechanics of movements, Norkin

30. Any Questions?