Module 9: Biomechanics and Motor Control of the Lower Extremity Flashcards
What are the bones of the pelvic girdle and lower limb?
Pelvic girdle: ilium, ischium, pubis, sacrum
Lower limb: femur, fibula, patella, tibia, foot bones
What is the function of the pelvic girdle in movement?
Support the weight of the body and allows for locomotion
What type of joint is the pubis symphysis?
Amphiartroses, little to no movement
Describe the SI joint in terms of it’s role in movement?
transmits weight of the body to the lower extremity,
absorbs impact during gait
experiences little to no movement
What type of joint is the hip joint?
Ball and socket (3 degrees of freedom)
What makes the hip joint more stable that the shoulder joint?
70% of the femur head makes contact with the acetabulum
acetabular labrum deepens the cavity and a thick capsule and strong ligaments
What are the roles of the muscles surrounding the hip?
Iliopsoas = hip flexors
Glutes: hip extension
Describe the knee joint in terms of its movement and injuries that can occur?
2 degrees of freedom, minimal rotation
- vulnerable to injuries due to the mechanical demands and reliance on soft tissue
What are the actions of the quads and hamstrings and calf muscles?
Quads: knee extension
Hamstrings: knee flexion
Gastroc: plantar flexion and knee flexion
What are the possible movements at the ankle joint?
Subtalar joint: eversion and inversion
Talocular: dorsifelxion and plantar flexion
What is the angle of inclination of the femur?
Angle formed by the femoral neck and the shaft in the frontal plane
- Normal is 125
> 125 = coxa valga
< 125 = coxa vara
Describe the angle of anteversion of the femur and what it can result in?
Angle formed by femoral neck and shaft on the transverse plane
- Normal is 14
> 14 = anteversion = toeing in
< 14 = retroversion = toeing out
Describe the Q angle of the knee?
Angle formed between the patella and ASIS
- Normal is 15
> 15 = genu valgum
< 15 = genu varum
What is the difference between an increased or decreased median longitudinal arch?
Increase = high arch = pes cavus
Decrease = flat foot = pes planus
What are the clinical implications of the angle of inclination of the femur (how does this impact the rest of the lower limb)?
Increased = coxa valga, genu varus (decreased Q angle), pes cavus
Decreased = coxa vara, genu valgus (increased Q angle), pes planus
What movements of the lower body need to occur in order to go from sitting to standing?
forward displacement of COG, knees flexed (90-115), hip flexion (120)
At what point is the most common for people to stall out when going from sitting to standing?
immediately after lifting off the chair (greatest moment of torque) quads and hip extensors are the most active here
