Kinesiology 2: Hip Joint Pathomechanics

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Questions and Answers

What is the primary role of the abductor muscles during weight-bearing activities?

They facilitate rotation of the femur.

They aid in flexing the hip joint.

They stabilize the pelvis and weight above it. (correct)

They promote extension of the knee joint.

Where do the abductor muscles attach to provide stability to the pelvis?

From the femur to the distal lumbar vertebrae.

From the sacrum to the tibia.

From the femur to the pelvis. (correct)

From the pelvis to the greater trochanter.

What happens when the abductor muscles on the support side contract?

They increase the range of motion of the knee.

They help maintain pelvic stability. (correct)

They assist in lateral flexion of the spine.

They cause the pelvis to tilt excessively.

Which of the following best describes the mechanism of action for the abductor muscles?

They create a pulling force from the femur to the pelvis. Signup and view all the answers

What is the consequence of weak abductor muscles on the support side?

Decreased stability and potential pelvic tilt. Signup and view all the answers

What position do the hips typically assume when an individual squats to lift something from the floor?

Hips slightly abducted Signup and view all the answers

Which nerve injury is associated with adductor weakness?

Obturator nerve injury Signup and view all the answers

What is a likely consequence of weakness in the adductor muscles?

Limited stabilization of the hip joint Signup and view all the answers

Why is adductor weakness considered uncommon?

It is not frequently associated with significant injuries Signup and view all the answers

Which of the following scenarios could potentially lead to adductor weakness?

An accident resulting in obturator nerve damage Signup and view all the answers

What is a significant characteristic of the adductor brevis regarding its function?

It has one of the largest adduction moment arms. Signup and view all the answers

In which position can the adductor brevis effectively perform hip adduction?

In any position of hip flexion. Signup and view all the answers

Which statement about the adductor brevis is false?

It solely contributes to hip flexion. Signup and view all the answers

Which muscle group does the adductor brevis belong to?

Adductor muscles. Signup and view all the answers

What role does the adductor brevis play in hip movement?

Enables hip adduction across various positions. Signup and view all the answers

What is a common cause of tightness in the adductor muscles?

Adaptive changes in non-stretched muscles Signup and view all the answers

Which statement accurately reflects the nature of adductor muscle tightness?

It often results from muscle routine adaptations. Signup and view all the answers

What is a potential consequence of not stretching frequently?

Development of tightness in certain muscles Signup and view all the answers

Which group of muscles is specifically mentioned as commonly experiencing tightness?

Adductors Signup and view all the answers

What does the term 'adaptive changes' in muscles refer to?

Physical modifications that occur from inactivity or lack of stretching Signup and view all the answers

What is the presumed effect of loss in muscle bulk as indicated in the content?

Diminished balance and stair climbing difficulty Signup and view all the answers

Which of the following outcomes is associated with age-related muscle loss?

Diminished balance Signup and view all the answers

How does loss of strength relate to muscle bulk and aging?

It may contribute to functional declines Signup and view all the answers

Which of the following statements is true regarding age-related muscle changes?

Diminished strength may lead to difficulty in stair climbing Signup and view all the answers

What physiological change is indicated to accompany age-related functional declines?

Loss in muscle bulk and strength Signup and view all the answers

What term describes the technique where an individual rests in maximum hyperextension to utilize ligament support?

Hanging on the ligaments Signup and view all the answers

What is the primary benefit of resting in maximum hyperextension?

To prevent additional backward bending Signup and view all the answers

Which statement best describes the effect of passive support from ligaments during maximum hyperextension?

It prevents undesirable movements. Signup and view all the answers

In which position is an individual likely to benefit from ligament support?

Maximum hyperextension Signup and view all the answers

What is a potential consequence of not utilizing ligament support during hyperextension?

Risk of overextending the back Signup and view all the answers

Study Notes

Presenter Information

Karim Ghuiba, lecturer of physical therapy at Cairo-Galala University
Doctor of Physical Therapy from New York, USA
Lecture date: 10/9/2024

Kinesiology 2 - Fall 2024

Course offered at Galala University
Focuses on the pathomechanics of the hip joint

Lecture 2: Pathomechanics of the Hip Joint

Focuses on the muscles of the hip joint

Muscles of the Hip Joint

Psoas Major: A strong hip flexor
- Smaller moment arm for flexion than other hip flexors
- Large physiological cross-sectional area (PCSA)
- Center of mass is posterior to the hip joint, creating extension moment
  - Muscle produces flexion moment to counteract this
- Better aligned to apply compressive loads to the lumbar spine, not for flexion/extension
  - Assists in stabilizing the spine
Iliacus: A large hip flexor, equal or greater than PCSA of psoas major
- Acts similarly to the psoas major, active during sit-ups and curl-ups
- Supports hip in upright standing to prevent HAT weight from hyperextending the hip
Psoas Minor: A trunk muscle, not a hip flexor, sometimes absent (~40% of population)
- Smaller and weaker than the psoas major
Gluteus Maximus: A major hip extensor, large muscle forming most of the buttocks
- Elicits activity in hamstrings and adductor magnus while ascending stairs
- Activity during single-stance wall squats and mini-squats
- More active during forceful hip extension from extended or hyperextended positions
Hip Abductors (Gluteus Medius & Minimus): Important during weight-bearing activities
- Gluteus Medius: hip abductor that can rotate the hip medially or laterally, depending on fibers
- Gluteus Minimus: another strong hip abductor that medially rotates the hip and potentially helps protect the hip capsule during movement

Effects of Weakness

Psoas Major: Weakness decreases hip flexion strength, causing difficulties with tasks like lifting limbs in/out of the bathtub and climbing stairs
Iliacus: Weakness decreases hip flexion strength and can lead to hyperextension of the hip
Gluteus Maximus: Weakness causes decreased hip extension and lateral rotation, and can result in a "gluteus maximus lurch" during gait.
Hip Abductors (Gluteus Medius & Minimus):
- Weakness leads to a significant decrease in hip abduction strength
- Instability and abducted gait in single-limb support -Pelvis drops on the unsupported side during weight-bearing activities

Effects of Tightness

Psoas Major: Tightness restricts hip extension and trunk side-bending flexibility. Increased lumbar extension (lordosis)
Iliacus: Tightness results in anterior pelvic tilt and hyperextension of the lumbar spine
Gluteus Maximus: Tightness limits hip range of motion (ROM) in flexion, medial rotation and possibly adduction
Hip Abductors (Gluteus Medius & Minimus): Tightness limits ROM in adduction and possibly lateral rotation, often associated with arthritis.

Hip Adductors

Pectineus: consistent actions of flexion and adduction, active in medial rotation
Adductor Brevis: large adduction moment, active in medial rotation during hip flexion
Adductor Longus: exhibits consistent medial rotation moment, more consistent role in hip flexion and adduction than rotation
Adductor Magnus: large muscle, substantial hip adduction ability

Functional Roles of Muscles

Adductors stabilize the pelvis during weight shifting between limbs in gait and during squatting.

Lateral Rotators

Piriformis
Obturator Internus
Superior and Inferior Gemelli
Quadratus Femoris
Obturator Externus

General

Weakness and Tightness of Lateral Rotators Difficult to isolate
Medial Rotators No muscle dedicated to medial rotation

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Description

This quiz covers the second lecture of Kinesiology 2 focusing on the pathomechanics of the hip joint. It explores the roles and functions of key muscles involved such as the Psoas Major and Iliacus. Test your knowledge on their mechanics and contributions to hip joint movement.