Chapter 13 Flashcards
What is the primary requirement for movement to take place in strength training?
Internal Torque must exceed the External Torque.
What must increase for movement to occur in strength training?
Muscle Force (Internal) must increase.
In free exercises, what factors change the external torque?
The position of the body as a whole and the positions of the active limbs.
What muscles are needed to exert torque of the upper body during a Trunk Curl Sit-up?
Rectus Abdominis, External & Internal Obliques, Psoas, Iliacus, Adductors, Gracilis.
What is the plane and axis involved in a Trunk Curl Sit-up?
Sagittal Plane / ‘x-axis’.
What happens to the External Moment Arm (d1) at Stage One of a sit-up?
The External Moment Arm decreases.
Where is the most strenuous part of the sit-up?
Just after the start of the motion when the External Moment Arm – d1 is the longest.
How can we increase the difficulty of a sit-up?
Increase the external moment arm.
What occurs to the External Torque during Stage Two of a sit-up?
The External Moment Arm gradually decreases.
Which muscles rotate the upper body about the hips to an upright sitting position during a sit-up?
Hip Flexors.
What happens to the moment-arm of the hip flexors if the legs remain extended during a sit-up?
The moment-arm of the hip flexors remains unchanged.
What is the advantage of performing a Bent-leg Sit Up?
It makes it easier to initiate the sit-up due to increased moment-arm length of the hip flexors.
Why can Leg Raises be prescribed if the abdominals and hip flexors are incapable of initiating a sit-up?
Leg Raises have a moment arm of the weight of the leg that is approximately the same as the upper body during the trunk curl.
What percentage of body weight does the weight of the leg represent?
Approximately 16% of body weight.
What causes lower back injuries during sit-ups?
Excessive anterior pelvic tilt increases lumbar curvature.
What is the key alignment during a push-up?
Head, trunk, & legs are held in alignment.
What joints and muscles constitute the ‘mover’s’ in the push-up lever system?
G.H. Joint and Elbow.
What external moment arm is involved in the push-up?
From ankle joint to the point of location of the Body Weight (W).
What happens to the external moment arm as the angle of inclination increases in a push-up?
The external moment arm derived from body weight increases.
How can you reduce the external moment arm in a push-up to make the progression easier?
Use the knees as a fulcrum.
List the active muscle groups during a Half Squat.
Hip Extensors, Knee Extensors, Ankle Plantar Flexors.
How does the external moment arm impact the demands on muscles during squats?
A larger external moment arm makes greater demands on the muscles.
In which position do the Hip Extensors need to work harder: inclined or erect?
Position 1: Inclined.
In which position do the Knee Extensors need to work harder: inclined or erect?
Position 2: Erect.
In which position do the Plantar Flexors need to work harder: inclined or erect?
Position 1: Inclined.
What is the effect of the line of action of the weight on the training effect of the Hip Extensors in the Supine Leg-Press?
Minimal training effect in Position 1.
What happens to the training effect of Knee Extensors and Plantar Flexors in Position 1 of the Supine Leg-Press?
Both muscle groups will feel a greater training effect.
How do slight changes in body posture affect training demands on muscle groups?
They significantly change the external moment arms.
What is the primary requirement for movement to take place in strength training?
Internal Torque must exceed External Torque, and Muscle Force must increase.
Which exercises are examined in the lecture?
Sit-Up, Leg Raises, Push-up, Squats, Leg press - vertical.
What happens to the External Moment Arm at Stage One of the Trunk Curl Sit-up?
The External Moment Arm decreases.
Which muscles are needed to exert torque of the upper body during the Sit-up?
Rectus Abdominis, External & Internal Obliques, Psoas, Iliacus, Adductors, & Gracilis.
How does the position of the body affect external torque in free exercises?
The position of the body as a whole and the positions of the active limbs will change the external torque.
What is the most strenuous part of the sit-up?
The beginning.
How can we make the sit-up exercise more difficult?
Increase the external moment arm.
What occurs during Stage Two of the Sit-up?
The Hip Flexors and the Internal Moment Arm must overcome the External Torque.
What muscles are responsible for bringing the body to an upright position during the sit-up?
The Hip Flexors.
What effect does bending the knees have on the internal torque during a sit-up?
It decreases the demands on the Hip Flexors.
Why can leg raises be prescribed if the Abdominals and Hip Flexors are incapable of initiating a Sit-up?
Because they are easier due to the leg’s weight being less than the upper body weight.
How do lower back injuries from sit-ups occur?
By excessive anterior pelvic tilt increasing the lumbar curvature.
What should be strengthened to reduce lower back injury risks during sit-ups?
Strengthen abdominals so that hip flexors do not perform the majority of the work.
What joints and muscles are involved in the push-up lever system?
G.H. Joint and Elbow.
What is the moment arm consideration in the push-up?
Greater angle of inclination increases the external moment arm and external torque.
What are the active muscle groups in the Half Squat?
Hip Extensors, Knee Extensors, Ankle Plantar Flexors.
What happens when the external moment arm is larger?
It makes greater demands on the muscles at the specific joints.
In which position do the Hip Extensors need to work harder during a squat?
Position 1: Inclined.
In which position do the Knee Extensors need to work harder?
Position 2: Erect.
What changes can significantly affect the training demands of muscle groups in focus?
Slight changes in body posture.
What is a primary requirement for movement to take place in strength training?
Internal Torque must exceed the External Torque.
Which muscle force must increase for movement to occur in strength training?
Muscle Force (Internal) must increase.
In free exercises like push-ups and sit-ups, what changes the external torque?
The position of the body and the positions of the active limbs.
What is the first stage in performing a Trunk Curl Sit-up?
Flexion of the neck and thoracic spine.
Which muscles are primarily used to exert torque during a sit-up?
Rectus Abdominis, External & Internal Obliques.
In which plane and axis does the Trunk Curl Sit-up occur?
Sagittal Plane / ‘x-axis’.
What happens to the External Moment Arm at Stage One of a sit-up?
The External Moment Arm decreases.
What is the most strenuous part of the sit-up according to the progress of the trunk flexors?
Beginning.
How can the difficulty of a sit-up be increased?
By increasing the external moment arm.
What occurs to the External Torque at Stage Two of a sit-up?
The External Moment Arm gradually decreases.
Which muscles must overcome the External Torque during the second part of the sit-up?
The Hip Flexors.
What happens to the moment-arm of the hip flexors if the legs remain extended during a sit-up?
The moment-arm remains unchanged.
When is a Bent-leg Sit Up performed?
If Abdominals and Hip Flexors are incapable of initiating the sit-up.
What changes in the internal torque make it easier to sit up with bent knees?
Increased length of the moment arm of the hip flexors.
What happens to the demands on the hip flexors when performed with bent knees?
Decreases the demands on the Hip Flexors.
Why can Leg Raises be prescribed?
If the Abdominals and Hip Flexors are incapable of initiating the Sit-Up.
Why is it easier to perform a leg raise compared to a bent-leg sit-up?
The weight of the leg is approx. 16% of the body, while the upper body is approx. 68%.
How can lower back injuries be caused by sit-ups?
Excessive anterior pelvic tilt increases lumbar curvature.
What should be done to reduce the risk of lower back injury during sit-ups?
Strengthen abdominals to prevent hip flexors from doing most of the work.
What alignment should be maintained in a Push-up?
Head, trunk, and legs held in alignment.
What are the joints involved in the ‘mover’s’ system during a Push-up?
G.H. Joint and Elbow.
What is the joint motion at the G.H. joint during the ‘Up Phase’ of a Push-up?
Horizontal Adduction and Flexion depending on hand position.
What happens to the moment arm in the Push-up as the angle of inclination increases?
The external moment arm from body weight increases.
What determines the training effect on the muscles with greater external moment arms?
They will have to work harder.
Which position requires the Hip Extensors to work harder?
Position 1: Inclined.
In which position do the Knee Extensors need to work harder?
Position 2: Erect.
What is the line of action in Position 1 of the Supine Leg-Press?
It passes directly through the x-axis of the hip joint.
What is the training effect on the Hip Extensors in Position 1 of the Supine Leg-Press?
Minimal training effect due to the line of action passing through the x-axis.
What effect do slight changes in body posture have during exercise?
They can significantly change the training demands on muscle groups due to changes in the external moment arms.
What is the primary requirement for movement to take place in strength training?
Internal Torque must exceed the External Torque, and Muscle Force (Internal) must increase.
What are some exercises examined in this lecture?
Sit-Up, Leg Raises, Push-up, Squats, Leg press - vertical.
In the case of free exercises like push-ups and sit-ups, what affects the external torque?
The position of the body as a whole and the positions of the active limbs.
What is the significance of the internal moment arm in strength training?
In specific cases, the Internal Moment Arm can be changed by repositioning the limbs.
What muscles are required to exert torque during the trunk curl sit-up?
Rectus Abdominis, External Obliques, Internal Obliques, Hip Flexors (Psoas, Iliacus, Adductors, Gracilis).
What happens to the external moment arm (d1) at Stage One of the trunk curl sit-up?
The External Moment Arm decreases.
Where is the most strenuous part of the sit-up?
At the beginning of the movement.
How can the exercise be made more difficult during the sit-up?
By increasing the external moment arm.
What occurs during Stage Two of the sit-up?
The hip flexors and the internal moment arm must overcome the external torque.
What is the effect of flexing knees during a bent-leg sit-up compared to straight legs?
The moment arm of hip flexors is maximized, which makes the sit-up easier.
Why would leg raises be prescribed in strength training?
If the abdominals and hip flexors are incapable of initiating the sit-up.
What is the difference in weight contribution between the legs and the upper body during leg raises?
The weight of the leg is approx. 16% of the body weight, while the upper body is approx. 68%.
How can lower back injuries be caused by sit-ups?
Excessive anterior pelvic tilt, increasing lumbar curvature.
What are the muscle groups active during a push-up?
Pectoralis Major, deltoid, triceps.
What joint motions occur during the up phase of a push-up?
Horizontal adduction and flexion at the G.H. joint.
What happens to the external moment arm in the push-up as the angle of inclination increases?
The external moment arm derived from body weight increases, leading to larger external torque.
What muscle groups are involved in the half squat?
Hip Extensors, Knee Extensors, Ankle Plantar Flexors.
How does the external moment arm affect the training effect on muscles?
A larger external moment arm leads to greater demands on muscles, resulting in a greater training effect.
What happens to the external moment arm of the hip extensors in inclined vs. erect positions?
D H1 > D H2 in inclined; the hip extensors need to work harder.
How does body posture affect muscle training demands?
Slight changes in body posture can significantly change the training demands due to changes in the external moment arms.
What is the primary requirement for movement to take place in strength training?
Internal Torque must exceed External Torque, and Muscle Force must increase.
Which exercises are examined in the lecture?
Sit-Up, Leg Raises, Push-up, Squats, Leg press - vertical.
What happens to the External Moment Arm at Stage One of the Trunk Curl Sit-up?
The External Moment Arm decreases.
Which muscles are needed to exert torque of the upper body during the Sit-up?
Rectus Abdominis, External & Internal Obliques, Psoas, Iliacus, Adductors, & Gracilis.
How does the position of the body affect external torque in free exercises?
The position of the body as a whole and the positions of the active limbs will change the external torque.
What is the most strenuous part of the sit-up?
The beginning.
How can we make the sit-up exercise more difficult?
Increase the external moment arm.
What occurs during Stage Two of the Sit-up?
The Hip Flexors and the Internal Moment Arm must overcome the External Torque.
What muscles are responsible for bringing the body to an upright position during the sit-up?
The Hip Flexors.
What effect does bending the knees have on the internal torque during a sit-up?
It decreases the demands on the Hip Flexors.
Why can leg raises be prescribed if the Abdominals and Hip Flexors are incapable of initiating a Sit-up?
Because they are easier due to the leg’s weight being less than the upper body weight.
How do lower back injuries from sit-ups occur?
By excessive anterior pelvic tilt increasing the lumbar curvature.
What should be strengthened to reduce lower back injury risks during sit-ups?
Strengthen abdominals so that hip flexors do not perform the majority of the work.
What joints and muscles are involved in the push-up lever system?
G.H. Joint and Elbow.
What is the moment arm consideration in the push-up?
Greater angle of inclination increases the external moment arm and external torque.
What are the active muscle groups in the Half Squat?
Hip Extensors, Knee Extensors, Ankle Plantar Flexors.
What happens when the external moment arm is larger?
It makes greater demands on the muscles at the specific joints.
In which position do the Hip Extensors need to work harder during a squat?
Position 1: Inclined.
In which position do the Knee Extensors need to work harder?
Position 2: Erect.
What changes can significantly affect the training demands of muscle groups in focus?
Slight changes in body posture.
What is a primary requirement for movement to take place in strength training?
Internal Torque must exceed the External Torque.
Which muscle force must increase for movement to occur in strength training?
Muscle Force (Internal) must increase.
In free exercises like push-ups and sit-ups, what changes the external torque?
The position of the body and the positions of the active limbs.
What is the first stage in performing a Trunk Curl Sit-up?
Flexion of the neck and thoracic spine.
Which muscles are primarily used to exert torque during a sit-up?
Rectus Abdominis, External & Internal Obliques.
In which plane and axis does the Trunk Curl Sit-up occur?
Sagittal Plane / ‘x-axis’.
What happens to the External Moment Arm at Stage One of a sit-up?
The External Moment Arm decreases.
What is the most strenuous part of the sit-up according to the progress of the trunk flexors?
Beginning.
How can the difficulty of a sit-up be increased?
By increasing the external moment arm.
What occurs to the External Torque at Stage Two of a sit-up?
The External Moment Arm gradually decreases.
Which muscles must overcome the External Torque during the second part of the sit-up?
The Hip Flexors.
What happens to the moment-arm of the hip flexors if the legs remain extended during a sit-up?
The moment-arm remains unchanged.
When is a Bent-leg Sit Up performed?
If Abdominals and Hip Flexors are incapable of initiating the sit-up.
What changes in the internal torque make it easier to sit up with bent knees?
Increased length of the moment arm of the hip flexors.
What happens to the demands on the hip flexors when performed with bent knees?
Decreases the demands on the Hip Flexors.
Why can Leg Raises be prescribed?
If the Abdominals and Hip Flexors are incapable of initiating the Sit-Up.
Why is it easier to perform a leg raise compared to a bent-leg sit-up?
The weight of the leg is approx. 16% of the body, while the upper body is approx. 68%.
How can lower back injuries be caused by sit-ups?
Excessive anterior pelvic tilt increases lumbar curvature.
What should be done to reduce the risk of lower back injury during sit-ups?
Strengthen abdominals to prevent hip flexors from doing most of the work.
What alignment should be maintained in a Push-up?
Head, trunk, and legs held in alignment.
What are the joints involved in the ‘mover’s’ system during a Push-up?
G.H. Joint and Elbow.
What is the joint motion at the G.H. joint during the ‘Up Phase’ of a Push-up?
Horizontal Adduction and Flexion depending on hand position.
What happens to the moment arm in the Push-up as the angle of inclination increases?
The external moment arm from body weight increases.
What determines the training effect on the muscles with greater external moment arms?
They will have to work harder.
Which position requires the Hip Extensors to work harder?
Position 1: Inclined.
What is the line of action in Position 1 of the Supine Leg-Press?
It passes directly through the x-axis of the hip joint.
What is the training effect on the Hip Extensors in Position 1 of the Supine Leg-Press?
Minimal training effect due to the line of action passing through the x-axis.
What effect do slight changes in body posture have during exercise?
They can significantly change the training demands on muscle groups due to changes in the external moment arms.
What is the primary requirement for movement to take place in strength training?
Internal Torque must exceed the External Torque, and Muscle Force (Internal) must increase.
What are some exercises examined in this lecture?
Sit-Up, Leg Raises, Push-up, Squats, Leg press - vertical.
In the case of free exercises like push-ups and sit-ups, what affects the external torque?
The position of the body as a whole and the positions of the active limbs.
What is the significance of the internal moment arm in strength training?
In specific cases, the Internal Moment Arm can be changed by repositioning the limbs.
What muscles are required to exert torque during the trunk curl sit-up?
Rectus Abdominis, External Obliques, Internal Obliques, Hip Flexors (Psoas, Iliacus, Adductors, Gracilis).
What happens to the external moment arm (d1) at Stage One of the trunk curl sit-up?
The External Moment Arm decreases.
Where is the most strenuous part of the sit-up?
At the beginning of the movement.
How can the exercise be made more difficult during the sit-up?
By increasing the external moment arm.
What occurs during Stage Two of the sit-up?
The hip flexors and the internal moment arm must overcome the external torque.
What is the effect of flexing knees during a bent-leg sit-up compared to straight legs?
The moment arm of hip flexors is maximized, which makes the sit-up easier.
Why would leg raises be prescribed in strength training?
If the abdominals and hip flexors are incapable of initiating the sit-up.
What is the difference in weight contribution between the legs and the upper body during leg raises?
The weight of the leg is approx. 16% of the body weight, while the upper body is approx. 68%.
How can lower back injuries be caused by sit-ups?
Excessive anterior pelvic tilt, increasing lumbar curvature.
What are the muscle groups active during a push-up?
Pectoralis Major, deltoid, triceps.
What joint motions occur during the up phase of a push-up?
Horizontal adduction and flexion at the G.H. joint.
What happens to the external moment arm in the push-up as the angle of inclination increases?
The external moment arm derived from body weight increases, leading to larger external torque.
What muscle groups are involved in the half squat?
Hip Extensors, Knee Extensors, Ankle Plantar Flexors.
How does the external moment arm affect the training effect on muscles?
A larger external moment arm leads to greater demands on muscles, resulting in a greater training effect.
What happens to the external moment arm of the hip extensors in inclined vs. erect positions?
D H1 > D H2 in inclined; the hip extensors need to work harder.
How does body posture affect muscle training demands?
Slight changes in body posture can significantly change the training demands due to changes in the external moment arms.
