Kinesiology Lab: Lower Extremity Mechanics

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the type of the patellofemoral joint?

Synovial, pivot

Synarthrosis, fibrous

Diarthrosis, hinge

Diarthrosis, planar (correct)

Which position is considered close-packed for the talocrural joint?

Full extension

Full flexion

Maximum plantarflexion

Maximum dorsiflexion (correct)

What is the capsular pattern for the talocrural joint?

EV > INV

DF > PF

AB > AD

PF > DF (correct)

How many degrees of inversion are available at the subtalar joint?

20-30º Signup and view all the answers

What degree of functional inversion is required for gait?

4-6 degrees Signup and view all the answers

What is the total range of inversion and eversion for walking?

9-12º Signup and view all the answers

Which position of the subtalar joint is considered loose-packed?

Pronation Signup and view all the answers

During the biphasic gait cycle, what occurs at the midstance phase?

The leg is in a neutral position Signup and view all the answers

What type of end-feel is associated with inversion movements?

Firm Signup and view all the answers

Which statement accurately describes the pelvifemoral rhythm during forward rotation?

It results in medial rotation at the left hip. Signup and view all the answers

Which phase marks the transition into hip locking during gait?

Push-off Signup and view all the answers

What is the primary characteristic of the capsular pattern of ankle movements?

Inversion > Eversion Signup and view all the answers

In what position does the pelvis maintain a balance of joint reaction forces?

Neutral position Signup and view all the answers

What primarily causes a Trendelenburg gait?

Weakness in the gluteus medius muscle Signup and view all the answers

Why should a cane be used on the opposite side of a weak hip?

To create a lever effect that counters weight on the weak hip Signup and view all the answers

What effect does a change in the angle of inclination of the femoral neck have on hip abductor muscles?

Decreased moment arm for hip abductors Signup and view all the answers

Is the direction of coxa vara beneficial when performing a total hip replacement?

Yes, it reduces risk of dislocation Signup and view all the answers

How does weak hip abductors affect the quadratus lumborum?

It results in increased activation on the opposite side Signup and view all the answers

What happens to the mechanical axis of the lower extremity during dynamic activities?

It shifts medially, increasing force on the medial knee Signup and view all the answers

What role does the tensile force of the MCL play during knee dynamics?

It controls valgus motion and stabilizes the joint Signup and view all the answers

What is patella alta and how does it affect the kinematics of the PFJ during flexion?

Increased compressive JRFs and delayed knee flexion. Signup and view all the answers

Under relaxed standing conditions, how are weightbearing forces distributed at the knee?

Equally between the medial and lateral condyles Signup and view all the answers

Which term describes a patella positioned lower than normal, potentially affecting knee kinematics?

Patella baja Signup and view all the answers

What is the typical range for the Q-angle in a healthy knee?

10-15° Signup and view all the answers

Which of the following describes the motion associated with active ankle dorsiflexion (OKC)?

Abduction and eversion. Signup and view all the answers

What is the primary motion of the talus during closed kinetic chain (CKC) dorsiflexion?

Medial rotation of the tibia and fibula. Signup and view all the answers

How many degrees of rotation does the talus typically have during small talar motions?

5-10° Signup and view all the answers

What axis orientation of the talus contributes to triplanar motion of the ankle?

Inclined 14° in the transverse plane. Signup and view all the answers

In what way does the orientation of the quadriceps influence the PFJ?

Creates a posteriorly directed vector of force. Signup and view all the answers

What role does the soleus play in knee stability during weightbearing activities?

Assists in posterior tibial translation Signup and view all the answers

Which muscle group counteracts the anterior translation caused by quadriceps contraction?

Hamstrings Signup and view all the answers

At what knee flexion angle does the quadriceps generate peak moment capacity?

45-60° Signup and view all the answers

What effect does isometric quadriceps contraction have on the ACL in full knee extension?

Causes anterior tibial translation Signup and view all the answers

Why is neuromuscular control important in sports for ACL injury prevention?

It allows for balanced muscle force interactions. Signup and view all the answers

What does the patella primarily do regarding quadriceps strength in knee extension?

Increases the moment arm Signup and view all the answers

What is the status of the graft and attachment site 2-4 weeks post-ACL repair?

It is weakest. Signup and view all the answers

What is a potential consequence of co-activating opposing muscle groups?

Increase in compressive joint reaction forces Signup and view all the answers

What is the total weight that the hip has to support during unilateral stance?

5/6 of the body weight Signup and view all the answers

How does the moment of gravity affect the pelvis in relation to hip abduction and adduction?

It causes right adduction moment on the left hip. Signup and view all the answers

What is the role of hip abductor muscles during unilateral stance?

They provide a counteracting moment. Signup and view all the answers

Which values are required to calculate the moment generated by the hip abductor muscles?

Force and moment arm. Signup and view all the answers

Why might someone with hip osteoarthritis lean their trunk over the painful hip during single leg stance?

To reduce the moment arm and decrease stress on the hip. Signup and view all the answers

What happens to the hip joint when transitioning to unilateral stance?

The femoral head experiences increased compressive force. Signup and view all the answers

If the moment arm (MA) for the hip abductors is 0.05 m, how is the moment generated calculated?

By multiplying hip abductor force by MA. Signup and view all the answers

Study Notes

Kinesiology Lab: December 3, 2024

Learning Outcomes: Students will be able to describe the classifications, kinematics, and unique characteristics of the hip, knee, ankle, and foot. Predict effects of different joint restrictions on lower extremity (LE) function for balance and gait. Extend knowledge of kinesiology to exercise prescription.

Summary of LE Kinematics

Review anatomy class information on joint classification.
Understand the range of motion (ROM) needed for function.
Learn about loose- and close-packed positions of joints and capsular patterns and end-feels.

Coxofemoral (Hip) Joint

Type: Diarthrotic, spheroidal (ball-and-socket).
Degrees of Freedom (DOF): 3 (flexion-extension, abduction-adduction, lateral-medial rotation).
Physiological ROM: Flexion (110-120°), extension (10-15°), abduction (30-50°), adduction (30°), lateral rotation (40-60°), medial rotation (30-40°).
Functional ROM varies by activity (e.g., tying shoes, sitting, squatting). Example measures given in degrees of sagittal, frontal, and transverse planes.

Tibiofemoral (Knee) Joint

Type: Diarthrotic, hinge.
DOF: 1 (flexion-extension).
Physiological ROM: Flexion (135°), extension (15° hyperextension), internal rotation (20-30°), external rotation (30-40°).
Functional ROM varies by activity (e.g., walking, stairs).

Patellofemoral Joint

Type: Diarthrotic, planar.
DOF: 0 (functionally allows superior-inferior and medial-lateral glide).
End-feel: Firm in all directions.

Talocrural (Ankle) Joint

Type: Diarthrotic, hinge.
DOF: 1 (dorsiflexion-plantarflexion).
Physiological ROM: Dorsiflexion (10-15°/20°), plantarflexion (50-70°).
Functional ROM varies by activity (e.g., walking, stairs).
End-feel: Dorsiflexion: firm/hard, Plantarflexion: firm/hard

Subtalar Joint

Type: Diarthrotic, plane.
DOF: 0 (functionally allows abduction-adduction and eversion-inversion).
Physiological ROM: Inversion (20-30°), eversion (5-10°).

Functional ROM for Gait

Inversion (4-6°), eversion (4-6°).
Combined motion allows for necessary pronation and supination during walking.

Pelvifemoral Rhythm

Pelvic rotation during gait.
Forward/backward rotation relates to medial/lateral hip rotation.

Compensatory Motions

Table showing relationships of pelvis, hip joint, and lumbar spine during right lower extremity weight-bearing and upright posture.

Application Questions

Impact of decreased lateral lumbar flexion, medial/lateral hip rotation on gait cycle.
Effect of increased body weight on femoral neck fracture risk.
Effect of osteoporosis on femoral neck fracture risk.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz focuses on the kinematics and classifications of the hip, knee, ankle, and foot, essential for understanding lower extremity function. Students will explore joint restrictions and their effects on balance and gait, integrating knowledge necessary for exercise prescription. Prepare to assess anatomical details and functional ranges of motion for each joint.