Muscle Complex Movements

Question 1

What are the traits of bipedal standing

Answer 1

Relatively small area of contact with the ground
Plantar surface of feet
Energy Efficient

Question 2

What roles can gravity have on muscles

Answer 2

Can act agonistic or antagonistic

Question 3

Describe the line of gravity through the body

Answer 3

It passes down posteriorly to the hip, anterior to the knee, and anterior to the ankle

Question 4

Explain the effect of gravity on the hip for bipedal standing

Answer 4

Passes posterior to the hip
Pushing joint into extension
Extension = reinforcing capsular ligaments are tight
Joint is locked

Question 5

Explain the effects of gravity on the knee joint for bipedal standing

Answer 5

Passes anteriorly to joint
Joint is pushed into extension
Extension = posterior cruciate ligament tight
Joint is locked

Question 6

Explain the effects on the ankle joint for bipedal standing

Answer 6

Anterior to joint
“Fall” into dorsiflexion (no ligament preventing dorsiflexion)
Plantarflexors stabilise
Energy is consumed

Question 7

Where is most of the energy expended in a bipedal stance

Answer 7

The ankle joint

Question 8

What are the stance and swing phases

Answer 8

Early, mid, and late stance
Early, mid, and late swing

Question 9

What is the early stance

Answer 9

Hip - in flexion, moving into extension (concentric action of gluteus maximus and hamstrings.
Knee - locked in extension (posterior cruciate ligament - isometric activity of quadriceps femoris, and hamstrings + gastrocnemius)
Ankle - In dosiflexion (stable - best bony congruence), moving into planntarflexion (concentric activity triceps surae, eccentric activity tibialis anterior)

Question 10

What is the mid stance

Answer 10

Hip - Moving to extension (concentric activity gluteus maximus and hamstrings)
Knee - Moving from extention into slight flexion (concentric action hamstrings + gastrocnemius - occurs due to hamstring activity at hip and gastrocnemius activity at ankle)
Ankle - moving into plantarflexion (concentric action of triceps surae and gastrocnemius)

Question 11

What is late stance

Answer 11

Hip - in extension (concentric activity of gluteus maximus and hamstrings)
Knee - in extention (moving into flexion) as ankle moves into full plantarflexion (concentric action of hamstring + gastrocnemius to anticipate moving into flexion)
Ankle - In plantarflexion (concentric action of triceps surae)

Question 12

What is early swing

Answer 12

Hip - in extension, moving into flexion (concentric activity of iliopsoas and rectus femoris, eccentric activity of gluteus maximus and hamstrings controls swing)
Knee - in flexion (concentric action of hamstrings and gastrocnemius)
Ankle - in dorsiflexion (concentric action of tibialis anterior)

Question 13

What is mid swing

Answer 13

Hip - in flexion (concentric activity of iliopsoas and rectus femoris, eccentric activity of gluteus maximus and hamstrings to control rate of swing)
Knee - in flexion (concentric action of hamstrings and gastrocnemius)
Ankle - in dorsiflexion (concentric action of tibialis anterior)

Question 14

What is late swing

Answer 14

Hip - In flexion (concentric activity of iliopsoas and rectus femoris, eccentric activity of gluteus maximus and hamstrings)
Knee - in flexion moves to extension for heel strike (concentric action of quadriceps femoris)
Ankle - In dosiflexion most stable for heel strike (concentric action tibialis anterior, isometric triceps surae once locked)