Presentation on theme: "Gait and Gait Deviations"— Presentation transcript:
1Gait and Gait Deviations Learn the gait cycle at each point, by muscle, speed, and what needs to happen.Most important phase is initial contact.
2Normal Human Locomotion Initial ContactLoading ResponseMid-StanceTerminal StancePre-SwingInitial SwingMid-SwingTerminal SwingClassic model of human gait developed by Perry at Los Ranchos. But what is gait really? What is happening? It is the constant forward progression of our COG, and our legs keep up to prevent us from falling. But we have to preserve energy – and the body does a beautiful job of storing energy in the movements so it doesn’t fatigue us.
3Normal Human Locomotion INITIAL CONTACTHip = FlexedKnee = Nearly FlexedAnkle = NeutralGoal = Begin Stance- GRF is Posterior to ankle, creating PF MOMENTClassic model of human gait developed by Perry at Los Ranchos. But what is gait really? What is happening? It is the constant forward progression of our COG, and our legs keep up to prevent us from falling. But we have to preserve energy – and the body does a beautiful job of storing energy in the movements so it doesn’t fatigue us.
4Normal Human Locomotion INITIAL CONTACTGRF is Anterior to Knee and Hip, creating EXTENTION at knee, FLEXION at hipPassive extension aided by Quads and HamstringsGluts, Hamstrings HIGHLY active to overcome vectorGluts and Hams are acting STRONGLY here to overcome the strong flexion moment that is occuring at the hip. Passive knee extension is occuring due to placement of the vector, but is still maintained somewhat by a small quad/ham contraction present at the knee.
5Normal Human Locomotion LOADING RESPONSEHip = FlexedKnee = is FlexingAnkle = PlantarflexingGoals = Weight Acceptance, Shock Absorption, Advance body over heel rockerGRF is still Posterior to Ankle, now Posterior to KneeThis is where maximum PELVIC OBLIQUITY and STANCE PHASE KNEE FLEXION ARE AT MAX – at the point of opposite toe-off.
6Normal Human Locomotion LOADING RESPONSEEccentric Control of Pretibials helps create the 1st ROCKER15-18º Knee flexion as Shock Absorber30º Hip Flexion maintained, creating 2nd highest Torque, only to dorsiflexion1st rocker is at the ANKLE, where a fixed TC joint allows for forward progression of the Tibia as loading response is occuring
7Normal Human Locomotion LOADING RESPONSEHamstrings help during LR to stabilize hip, prevent trunk flexionThis is taken over by Gluts as stance progressesEccentric action of Gluts, Hams, Adductor Magnus1st rocker is at the ANKLE, where a fixed TC joint allows for forward progression of the Tibia as loading response is occuringhamstrings are highly active early in loading response, but become less so as stance phase progresses and gluts take over. Gluts are initially an extender, but become an abductor as we progress to midstance.
8Normal Human Locomotion LOADING RESPONSEPoint of PEAK PELVIC OBLIQUITY and maximum STANCE PHASE KNEE FLEXION occurs hereOpposite toe-off occurs here – helps to decrease overall vertical displacement of the bodyThe PEAK VERTICAL DISPLACEMENT OCCURS at MIDSTANCE
9Normal Human Locomotion MIDSTANCEHip = ExtendingKnee = ExtendingAnkle = DorsiflexingGoal = Advance body over stationary footGRF moves anterior to ankle, goes from post to ant. at kneeProgression of the 1st rocker occurs here. Moves from 10 degrees of PF to 5-7 of DF, using eccentric control of the soleus at first, moreso the Gastroc as midstance ends due to extension of the knee which is more mechanically efficient for the gastroc complex. Quads are extending knee EARLY in midstance as vector moves anteriorly, then decreasing activity due to passive movement of the knee into extension.
10Normal Human Locomotion MIDSTANCEEarly need for knee extensors, but not during late midstance due to placement of the force vectorEarly need for soleus for eccentric control, more on gastroc as knee extends for mechanical efficiency.Progression of the 1st rocker occurs here. Moves from 10 degrees of PF to 5-7 of DF, using eccentric control of the soleus at first, moreso the Gastroc as midstance ends due to extension of the knee which is more mechanically efficient for the gastroc complex. Quads are extending knee EARLY in midstance as vector moves anteriorly, then decreasing activity due to passive movement of the knee into extension.Since Soleus doesn't cross the knee, it is more active during the knee flexion part of LR/MS, then Gastroc becomes more active as it assists in knee extension as well as eccentric control of DF as the rocker continues.
11Normal Human Locomotion MIDSTANCEHip flexion decreases from 30º to 10º as midstance progressesVertical GRF reduced by upswing of contralateral side – still produce 2 ½ times body weight at peak on same side femoral headGluts active as extensor early, abd. lateStrong trendelemburg action as vector is quite medial in the frontal plane. This is fought early by glut medius, aided later by glut max as hip extension need is reduced.important point as people often feel hip/back pain early in amputee gait training. Stronger abductor force away from prosthetic side as patients don't like to wt shift creats increased vertical forces on the contralateral femoral head and an opposite lumbar sidebending will occur to compensate.Many of these patients will need lumbar mobilizations to correct facet joint abnormalities that occur with prolonged lumbar sidebending. Help Prevent This!!!!
12Normal Human Locomotion MIDSTANCEIn Amputees, the Vertical GRF is INCREASED on sound limb due to prosthetic foot- This is less with Flex foot than with SACH foot; reinforces need to know componentryStudy by Snyder, et al. Showed lack of dorsiflexion moment on prosthesis increases vertical GRF on sound limb – therefore increasing forces on that side and putting stress on sound limb.the more advanced componentry replicates that DF moment better, thus reducing stress on the sound side, but it still isn't the same as our own foot. Why? Limited ROM in prothetic ankle. Once the A/P range of motion is taken up, the forces get transmitted UP the chain to the knee and hip. The more that can be absorbed by the prosthesis, the less stress there is on the residual limb and the patients sound side.
13Normal Human Locomotion MIDSTANCEHip flexion decreases from 30º to 10º as midstance progressesVertical GRF reduced by upswing of contralateral side – still produce 2 ½ times body weight at peak on same side femoral headGluts active as extensor early, abd. lateStrong trendelemburg action as vector is quite medial in the frontal plane. This is fought early by glut medius, aided later by glut max as hip extension need is reduced.
14Normal Human Locomotion TERMINAL STANCEHip = ExtendingKnee = Extended, then flexingAnkle = DorsiflexedGoal = Advance body over forefoot rocker- GRF creates STRONG DF momentIt is at this point that the gastroc – soleus complex is the most active, controlling forward tibial progression AND beginning the heel off over the MET heads;
15Normal Human Locomotion TERMINAL STANCEMovement over the Forefoot Rocker occursHighest demand on gastroc-soleus as body vector moves outside the boundaries of the footMax dorsiflexion occurs at TOE-OFFforefoot rocker is now dependent on the prosthetic keel. Again, know the componentry. Is it a stiff keel? Is it a long toe lever? this has immediate ramifications on what goes on at the knee. If the toe lever is long, it will be less flexible than the human foot, thus creating a stronger extension moment at the knee and more force will have to be generated to create initial swing.if the toe lever is short, then knee flexion as terminal stance ends will come sooner in the cycle, creating a "drop off" effect and also affecting the sound hip as a quick but powerful abduction moment is created since stance phase is a fraction shorter.
16Normal Human Locomotion TERMINAL STANCENO muscle action at knee – this extension is created by external torque and GRF passing far anterior to jointJoint motion and forward progression created by momentum and swing of contralateral limb
17Normal Human Locomotion TERMINAL STANCEMild hip extension torque createdPassive hip extension aided by position of vector posterior to hipTFL helps control extension torqueVertical Magnitude of vector is similar here to LoadingSO where is there the most vertical forces on the body and joints? Loading response and terminal stance according to the vertical vector readings.
19Normal Human Locomotion PRESWINGDuring unloading of limb, PF activity is DECREASED; NO active push off during normal gaitDF torque decreases as MP joints reach 60° of extensionAgain, created by momentum, contralateral limb. All part of the bodies ability to conserve energy
20Normal Human Locomotion PRESWINGHip flexes using MOMENTUM, plus rectus femoris, sartorius and add. LongusAdd. Longus helps counteract hip abd. Created by contralateral off-loadingPELVIC ROTATION helps balance the limbs outPosterior rotation on the contralateral side effectively lengthens that leg and helps counterbalance the hip flextion created by the initiation of swing
21Normal Human Locomotion INITIAL SWINGHip = FlexingKnee = FlexingAnkle = DorsiflexingGoal = Clear foot and advance limb- Pre-tibs are active, helping reduce PF angle from 20° to around 5°Help prepare to clear the floor for Midswing
22Normal Human Locomotion INITIAL SWINGKnee continues to flex to 60°, assisted by MOMENTUM plus biceps femoris (short head), sartorius and gracilisHip flexed to 20° with help if iliacus, gracilis, sartorius, which help to flex both hip AND knee
23Normal Human Locomotion MIDSWINGHip = FlexingKnee = ExtendingAnkle = DorsiflexingGoal = Advance limb and clear foot- Rapid knee ext. from 60° to 30° is PASSIVE, assisted by MOMENTUM
24Normal Human Locomotion MIDSWING- EMG shows only MILD hip flexor activity, maintaining 30° angleGracilis, sartorius, iliacus stop in early midswing, hamstrings begin to decelerate limbRest of limb advancement is MOMENTUMReinforce the point about momentum creating a lot of movement.
25Normal Human Locomotion TERMINAL SWINGHip = FlexedKnee = ExtendingAnkle = NeutralGoal = Advance limb- Pretibs now act to place foot properly on the groundPrepares the foot for the HEEL ROCKER, and we start all over again.
26Normal Human Locomotion TERMINAL SWINGQuads active at end of TS, help fully extend knee along with PELVIC ROTATIONEccentric hamstrings, Gluts help control hip and knee to control stride length
28When are Muscles Active, When are they not? Initial Contact and Loading Response- Focus often on strong contraction of knee ext. in BK patients – not necessary due to strong ext. moment- Use of Gluts/Hamstrings EARLY in stance phase to overcome strong FLEXION vector at hip- Focus on HIP/BACK extention, as hams/gluts used primarily to stabilize back and counteract hip flexion momentRemember, Gluts become a hip abductor by midstance, so when concentrating your exercise regimen, remember that a full range of motion of hip extension exercises may not be necessary. Focus on when the muscles are active to optimize your training program.
29When are Muscles Active, When are they not? Midstance and Terminal Stance- Remember, quads active EARLY in midstance, but vector again moves ANTERIOR, becoming passive- Vector moves ANTERIOR to ankle, now fully reliant on prosthetic footRemember, Gluts become a hip abductor by midstance, so when concentrating your exercise regimen, remember that a full range of motion of hip extension exercises may not be necessary. Focus on when the muscles are active to optimize your training program.
30Understand the Components!!!! Exercises done on the toes of the prosthesis can let the patient feel what give there is to the prosthetic and how they can adjust with their musculature.Get patient to understand the give of the foot and knee they are on to assist with this stage of gait
31Understand the Components!!!! Exercises done on the toes of the prosthesis can let the patient feel what give there is to the prosthetic and how they can adjust with their musculature.Remember, the Alignment of the prosthesis is such that, no matter what the foot, patient should be able to maximize his or her roll over to closely match the sound side.Due to lack of MTP extension, forces are transmitted up the chain to knee/hip. Pt MUST allow MOMENTUM to transfer over the foot to allow for minimizing forces at higher joints
32When are Muscles Active, when are they not? Pre-Swing and Initial Swing- Knee flexion throughout this phase done by MOMENTUM, so use to your advantage- All action at the knee and below can be controlled with proper PELVIC motion and use of proper hip muscles to create vector
33When are Muscles Active, when are they not? Pre-Swing and Initial Swing- Ipsilateral Adductors help propel hip forward while counteracting strong abduction vector during off- loading- USE BOTH actions to your advantage during exercise prescription – adductors are BOTH stabilizers and protagonists
34When are Muscles Active, when are they not? Mid-Swing and Terminal Swing- Knee extension in Mid-Swing is PASSIVE. In AK’s, extension assist components help with this action- ipsilateral hip musculature stops here, now Hamstrings begin to fire to slow knee ext, prepare for stabilization of back
35When are Muscles Active, when are they not? Mid-Swing and Terminal Swing- Pre-tibs prepare foot in TS, but not appropriate for amputees. Foot position is essential to maximize properties of prosthetic foot – FOOT PLACEMENT ACTIVITIES- End range Pelvic Rotation, quads are essential here to prepare for IC
36IMPORTANT EXERCISES Eccentric Hamstrings, Concentric Quads Adductors as both STABILIZER and PRIME MOVERCreating MOMENTUM, using it to your advantageQUICK BURST exercises
37IMPORTANT EXERCISES SPEED OF CONTRACTION - too much time does not allow for release of normal energy and eliminates importance of MOMENTUM in helping propel body forwardTRANSITION EXERCISES- moving between cycles of gait, when to transition to next mode of ms contraction