Podcast
Questions and Answers
What is the primary pelvic movement during the single-limb support phase of the gait cycle?
What is the primary pelvic movement during the single-limb support phase of the gait cycle?
At what point in the gait cycle does the hip reach approximately 30 degrees of flexion?
At what point in the gait cycle does the hip reach approximately 30 degrees of flexion?
How much does the knee flex during the loading phase after heel contact?
How much does the knee flex during the loading phase after heel contact?
Which phase occupies the largest percentage of the gait cycle during walking?
Which phase occupies the largest percentage of the gait cycle during walking?
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What occurs during the loading response phase?
What occurs during the loading response phase?
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What action do the quadriceps perform during the loading phase of the gait cycle?
What action do the quadriceps perform during the loading phase of the gait cycle?
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What is the order of hip extension during the gait cycle?
What is the order of hip extension during the gait cycle?
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What action characterizes the early phase of mid swing regarding pelvis tilt?
What action characterizes the early phase of mid swing regarding pelvis tilt?
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What occurs during the unloading response in the gait cycle?
What occurs during the unloading response in the gait cycle?
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Which ligament of the knee primarily limits valgus movement at the tibia?
Which ligament of the knee primarily limits valgus movement at the tibia?
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What is the effect of flexion on the ligaments of the knee?
What is the effect of flexion on the ligaments of the knee?
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What role do the menisci play in knee biomechanics?
What role do the menisci play in knee biomechanics?
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What is the primary function of the anterior cruciate ligament (ACL)?
What is the primary function of the anterior cruciate ligament (ACL)?
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Which mechanism helps maintain knee extension with minimal muscle activation in a standing position?
Which mechanism helps maintain knee extension with minimal muscle activation in a standing position?
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What happens to knee rotation during extension?
What happens to knee rotation during extension?
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How do joint reaction forces work in the knee?
How do joint reaction forces work in the knee?
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What is the primary role of the quadriceps during midstance?
What is the primary role of the quadriceps during midstance?
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Which muscles are primarily responsible for propulsion in terminal stance?
Which muscles are primarily responsible for propulsion in terminal stance?
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During initial swing, what is the action of the hip flexors?
During initial swing, what is the action of the hip flexors?
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What happens during the pre-swing phase when the stance leg pushes off the ground?
What happens during the pre-swing phase when the stance leg pushes off the ground?
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In mid-swing, which muscles are responsible for controlling the momentum of the leg?
In mid-swing, which muscles are responsible for controlling the momentum of the leg?
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What is the primary function of the tibialis anterior during the swing phases?
What is the primary function of the tibialis anterior during the swing phases?
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Which phase involves the body fully suspended over the planted foot?
Which phase involves the body fully suspended over the planted foot?
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What occurs during the terminal swing phase as the leg prepares for heel strike?
What occurs during the terminal swing phase as the leg prepares for heel strike?
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Which ligament limits hyperextension and abduction of the hip joint?
Which ligament limits hyperextension and abduction of the hip joint?
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Which of the following myotomes is responsible for hip abduction?
Which of the following myotomes is responsible for hip abduction?
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What structure is primarily associated with the medial rotating muscles of the hip?
What structure is primarily associated with the medial rotating muscles of the hip?
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Which myotome is associated with knee extension?
Which myotome is associated with knee extension?
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What is the role of the Ischiofemoral Ligament in the hip joint?
What is the role of the Ischiofemoral Ligament in the hip joint?
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What is the primary function of the meniscus in the knee joint?
What is the primary function of the meniscus in the knee joint?
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Which dermatomes correspond to the upper thigh region?
Which dermatomes correspond to the upper thigh region?
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Which artery primarily supplies the hamstrings and adductors?
Which artery primarily supplies the hamstrings and adductors?
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How is the medial tibial plateau shaped compared to the lateral tibial plateau?
How is the medial tibial plateau shaped compared to the lateral tibial plateau?
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Which movement corresponds to a 'superior roll and inferior glide' of the femur?
Which movement corresponds to a 'superior roll and inferior glide' of the femur?
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What is the primary function of the superior gluteal artery?
What is the primary function of the superior gluteal artery?
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During internal rotation in open chain, what motion occurs at the femur?
During internal rotation in open chain, what motion occurs at the femur?
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What effect does lateral rotation have on the knee joint's congruency?
What effect does lateral rotation have on the knee joint's congruency?
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What happens during flexion in terms of movement at the head of the femur?
What happens during flexion in terms of movement at the head of the femur?
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In a closed chain scenario, which movement incurs a medial roll and glide of the acetabulum on the femur?
In a closed chain scenario, which movement incurs a medial roll and glide of the acetabulum on the femur?
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What is a consequence of the shape of the tibial plateaus in relation to their respective menisci?
What is a consequence of the shape of the tibial plateaus in relation to their respective menisci?
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Which muscle is attached to the Anterior Inferior Iliac Spine?
Which muscle is attached to the Anterior Inferior Iliac Spine?
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What structure does the Patellar ligament attach to?
What structure does the Patellar ligament attach to?
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Which of the following landmarks is associated with the biceps femoris long head?
Which of the following landmarks is associated with the biceps femoris long head?
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What major change occurs in a woman's body during pregnancy regarding cardiac function?
What major change occurs in a woman's body during pregnancy regarding cardiac function?
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The center of mass in pregnant women is displaced forward due to which factor?
The center of mass in pregnant women is displaced forward due to which factor?
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Which ligament is associated with the Medial Epicondyle of the Femur?
Which ligament is associated with the Medial Epicondyle of the Femur?
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What is a significant effect of pregnancy on breast tissue?
What is a significant effect of pregnancy on breast tissue?
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Which muscle is primarily associated with the Inferior/Superior Pubic Rami?
Which muscle is primarily associated with the Inferior/Superior Pubic Rami?
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Study Notes
Biomechanics of the Stance Limb
- Initial contact begins with the heel striking the ground. The pelvis tilts slightly anteriorly. The hip flexes ~30 degrees at the start of the gait cycle, extending gradually to ~10 degrees of hip extension. The knee is flexed ~5 degrees at heel contact, further flexing to ~10-15 degrees during loading.
- Loading response: The body weight is absorbed through the stance leg, and pelvic tilt becomes more anterior. Knee flexion continues. Quads are activated eccentrically during this phase. Pre-swing phase - the knee nears full extension until toe-off.
- Midstance: Body weight is fully supported by the stance leg. Knee extends and the body is suspended over the planted foot. The glutes and hip flexors are active in propelling the body forward.
- Terminal stance: Heel of the stance leg lifts off the ground and the body moves forward to prepare for swing. Gastrocnemius and soleus muscles propel the body forward. Hip flexors are activated.
- Pre-swing: The stance leg continues propelling the body forward to swing the other leg. Gastrocnemius and soleus muscles are active. Hip flexors initiate this forward movement.
- Initial swing: The swing limb begins once the foot leaves the ground. Knee flexion begins and hips continue to flex, driving the leg forward. Quadriceps assist in bringing the leg forward.
- Mid-swing: The leg directly moves beneath the body. The knee extends. Hip flexors move the leg forward. Hamstrings decelerate the leg to prepare for the next step. Tibialis anterior controls dorsiflexion.
- Terminal swing: The leg slows down before preparing for the next heel strike. The knee fully extends (concentric quad action) for the next step. Hamstrings eccentrically decelerate the leg.
Biomechanics of the Knee
- Knee ligaments: MCL (Medial Collateral Ligament) limits valgus (abduction of tibia), LCL (Lateral Collateral Ligament) limits varus (adduction of tibia), ACL (Anterior Cruciate Ligament) limits anterior translation of tibia/posterior translation of femur. PCL (Posterior Cruciate Ligament) limits posterior translation of tibia/anterior translation of femur.
- Joint reaction forces: Compressive forces are reduced by medial and lateral menisci. Screwhome mechanism (locking mechanism) allows to maintain knee extension with minimal extensor muscle activation.
- Arthrokinematics: Role of the meniscus in reducing localized pressure and improving joint stability, and increasing joint congruency. Shape of medial and lateral tibial plateau accommodates the shape of the menisci.
Additional Notes
- Pelvic Rhythm: The pelvis tilts posteriorly before the spine extends. The glutes and hamstrings pull the pelvis backward.
- Trendelenburg Sign: Contralateral pelvis drop, indicating weakness in the gluteus medius or minimus muscles.
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Description
This quiz tests your knowledge on the mechanics of the gait cycle, focusing on pelvic movements and knee function during various phases. Questions cover aspects such as leg support, flexion angles, and the roles of ligaments and menisci in knee biomechanics. Assess your understanding of how these elements contribute to efficient movement.
