Kinesiology: Gait Analysis Part II - Exam V Study Material

Throughout the gait cycle, nearly all LE muscles exhibit ____ bursts of electrical activity

Short

Muscles are considered to be ____ or ____

On or off

Muscles are ____ if the amplitude of EMG reaches a predetermined value above resting, otherwise it is ____

On; off

Average walking velocity is ____ m/s

1.37

____ ____:

- 1st: just prior to heel contact (20% of gait)

- 2nd: from 45-70% of gait cycle, which corresponds to opposite heel contact

- controls the forward angular momentum of the trunk

Erector spinae

____ ____:

- increased activity when the hip flexors are actively flexing the hip, between 20-40% and again at 70-90% of gait cycle

- stabilizes the pelvis and lumbar spine

Rectus abdominis

_____ ____:

- begins at terminal swing to initiate hip extension and prepare the musculature for weight acceptance at the beginning of stance (prevents "jackknifing" of the trunk)

- remains active from heel contact to mid stance

- largely inactive in swing phase until terminal swing

Gluteus Maximus

______ are active during the first 10% of the gait cycle

Hamstrings

____ _____:

- become eccentrically active before toe off

- active only in the first half of swing phase, 2nd half of swing is the result of forward momentum of the thigh

- primarily iliopsoas but assisted by rectus femoris

Hip flexors

_____ _____ key roles:

- advance the LE forward during swing

- lift the LE to allow for toe clearance during swing

Hip flexors

____ ____:

- stabilize the pelvis in the frontal plane

- control the slight lowering of the contralateral pelvis

- control the alignment of the femur in the frontal plane

- inadequate activation may result in excessive adduction of the femur and excessive valgus torque at the knee

Hip adductors

______ _____ & _____:

- primary hip abductors

- most active during the first 40% of the gait cycle, especially during SLS

Gluteus medius & minimus

Other roles of ____ ____ include:

- active toward the very end of swing phase in preparation for heel contact

- anterior fibers assist with hip flexion & IR

- posterior fibers assist with hip extension & ER

Gluteus medius

_____ _____ 2 bursts of activity during gait:

- 1st: occurs at heel contact to stabilize the hip through coactivation with hip extensors and ABDs

- 2nd: occurs just after toe off to assist with initiation of hip flexion

Hip adductors

_____ _____ ____:

- active throughout much of the stance phase

- move through the contralateral side of the pelvis forward in the horizontal plane

- assist with advancement of the swing limb

Hip internal rotators

_____ ____ ____;

- most active during early stance

- work in conjunction with the internal rotators to control alignment of the hip in the horizontal plane

- control pelvis rotation while the lower limb is fixed

- eccentric activation important to the control of IR of the lower limb in early stance

- inadequate strength or control may result in excessive IR of he femur, often seen in conjunction with excessive foot pronation

Hip external rotators