Energy expenditure in gait

1. What type of amputation has the greatest increase in metabolic cost for ambulation? Least increase?
*2. What is the increase in energy expenditure for wheelchair propulsion?
3. Which requires more energy: prosthesis or crutch walking?
*4. What muscles need to be strengthened for crutch walking?

Answers:
1. Greatest increase: vascular transfemoral (100%), least increase: Syme's (15%).
2. 9%.
3. Crutch.
4. Latissimus dorsi, triceps, biceps, quads, hip extensors, hip abductors.

Determinants of gait

What are the six determinants of gait?

1. Pelvic rotation: lengthens limb as it prepares to accept weight.

2. Pelvic tilt: Pelvis on the side of the swinging leg is lowered to lower COG at midstance.

3. Knee flexion in stance: lowers COG and absorbs shock of impact at heel strike.

4. Foot mechanisms: Ankle PF at heel strike smooths curve of falling pelvis.

5. Knee mechanisms: after midstance, knee extends as ankle PFs and foot supinates.

6. Lateral displacement of pelvis: toward the stance limb to make COG over base of support.

Gait characteristics

1. What is the stride length? Step length?
*2. What is the normal distribution between stance and swing phases?
3. What is the distribution between double limb and single limb support?
4. What is cadence?
5. What is a comfortable walking speed?
6. Where is the center of gravity?


Answers:
1. Stride is measured from successive points of contact of same foot. Step length is measured from points of contact of opposite feet (approx 15-20 in).
2. 60% in stance phase, 40% swing phase. Faster walking decreases time in stance phase.
3. Double support is 20% of gait cycle, single support is 80%.
4. Cadance is the number of steps per unit of time.
5. 3 MPH.
6. 5 cm anterior to the 2nd sacral vertebra.

Gait: swing phase

What are the swing phase subdivisions?

Answers:
In My Teapot

1. Initial swing: from lift of extremity off ground to maximum knee flexion

2. Midswing: from immediately following knee flexion to vertical tibia position

3. Terminal swing: from vertical tibia position just prior to initial contact.

Swing phase makes up 40% of the gait cycle.

Gait: stance phase

What are the five subdivisions of the stance phase?

Answer:
I Like My Tea Pre-sweetened

1. Initial contact: instant foot contacts ground

2. Loading response: from initial contact to lift of contralateral extremity from ground (wt shift)

3. Midstance: from lift of contralateral extremity to when ankles of both extremities are aligned.

4. Terminal stance: from ankle alignment in the frontal plane to just prior to inital contact of the contralateral (swinging) extremity.

5. Preswing: From initial contact of contralat extremity to just prior to lift off of ipsilateral extremity (wt shift)

Stance phase makes up 60% of gait cycle.

Finger deformities

1. What is the etiology of trigger finger?
*2. What is the etiology of mallet finger?
3. What is the treatment of mallet finger?

Answers:
1. Trauma to the flexor tendon, resulting in thickening and a nodule. Clicking or locking is felt when the nodule passes through the tendon sheath.
2. Rupture of the extensor tendon in the distal phalanx secondary to forceful flexion, resulting flexed DIP.
3. Splint to immobilize distal phalanx in hyperextension 6-12 wks. Surgical treatment for poor healing, volar subluxation, or avulsion > 1/3 of the bone.

Dupuytren's contracture

1. What is a Dupuytren's contracture?
2. What diseases are associated with Dupuytren's contracture?
3. What are the clinical symptoms of Dupuytren's contracture?
4. What is the treatment of Dupuytren's contracture?

Answers:
1. Fibrous contracture of the palmar fascia creating a flexion contracture at the MCP and PIP.
2. Epilepsy, pulmonary TB, alcoholism, DM.
3. Painless thickening of palmar surface and underlying fascia, most common at 4th and 5th digits.
4. Injection followed by forceful extension, rupturing skin and fascia. Modalitis. Surgical treatments including fasciotomy or amputation.