Biomechanics - Quiz About The Science Of Structure!

A larger-handled object is easier to turn because it provides a greater mechanical advantage. This means that a larger force can be applied to the object, resulting in a greater torque or turning effect. The larger handle allows for a greater lever arm, which increases the mechanical advantage. This makes it easier to overcome any resistance or friction and turn the object. Therefore, the statement is true.

Poor posture can be caused by various factors, including habits, congenital malformation, and paralysis of key postural muscles. Habits such as slouching or sitting for long periods can contribute to poor posture. Congenital malformation refers to structural abnormalities present at birth that can affect posture. Paralysis of key postural muscles can also lead to poor posture as these muscles play a crucial role in maintaining proper alignment. Therefore, any of the mentioned factors can be the cause of poor posture.

As individuals age, there are several changes in gait that occur. One of these changes is an increase in the time spent in the stance phase, which refers to the time when the foot is in contact with the ground during walking. This increase in stance phase time can be attributed to decreased muscle strength and flexibility in the elderly. Additionally, elderly individuals tend to have shorter step lengths compared to younger individuals. This can be due to decreased balance and coordination. Lastly, there is a decrease in vertical displacement, meaning that there is less upward movement during walking. This can be caused by reduced muscle power and joint stiffness. Therefore, all of the given statements are true regarding gait changes with age.

The term "STATIC" refers to non-moving or nearly non-moving systems. This means that these systems are stationary or have very little movement. It can be used to describe objects or systems that are not in motion or have a very minimal amount of movement.

The patient's tendency to cross the unsupported limb in front of the other during the swing phase indicates a spasticity of the hip adductors. These muscles are responsible for bringing the leg towards the midline of the body. When they are spastic, they can cause the leg to cross over the midline, leading to the observed movement pattern.

Lowering the center of gravity and increasing the base of support would make it easier for the client to maintain balance. Lowering the center of gravity by bending the knees or hips helps to create a more stable and balanced position. Increasing the base of support by widening the stance or spreading the feet apart provides a larger area of support, making it easier to maintain balance and stability. By combining these two actions, the challenge of balancing is decreased, making it easier for the client.

Increasing the cadence (step rate) and decreasing step length can help improve gait safety for a patient with poor balance. Increasing the cadence can help maintain stability by reducing the time spent on each foot, while decreasing step length can help prevent overreaching and potential loss of balance. Additionally, increasing the width of the walking base (the distance between the feet) can provide a more stable base of support, further enhancing gait safety for individuals with poor balance. Therefore, options B and C are both correct in this case.

Cadence refers to the number of steps taken per minute while walking. It is a measure of walking speed and can be used to assess the intensity of physical activity. Stride length, on the other hand, refers to the distance covered in a single step. Gait cycle refers to the sequence of movements that occur during one complete cycle of walking. Period of nonsupport refers to the time when both feet are off the ground during walking. Therefore, cadence is the most appropriate term used to describe walking speed.

A muscle that generates most of its force directly back into the joint is producing a stabilizing force. This means that the muscle is working to support and stabilize the joint, preventing it from moving or dislocating. This type of force helps to maintain the stability and integrity of the joint during movement or physical activity.

The law of motion best demonstrated when a person in a wheelchair gains speed when she pushes on the rims is the law of acceleration. This law states that an object will accelerate in the direction of the net force applied to it. In this scenario, when the person pushes on the rims of the wheelchair, she applies a force in the backward direction, causing the wheelchair to accelerate forward. This demonstrates the relationship between force and acceleration, which is described by the law of acceleration.

Raising the center of gravity and decreasing the base of support will increase the challenge of a person working on balance. By raising the center of gravity, the person's body will be less stable, requiring more control and effort to maintain balance. Decreasing the base of support means reducing the area of contact between the person and the ground, further increasing the difficulty of maintaining balance. Together, these changes create a more challenging balance task for the person.

Parkinsonism is a condition characterized by a difficulty in initiating gait or movement. It is a neurological disorder that affects the brain's ability to control movement and coordination. This slowness in initiating gait is often seen as a common symptom of Parkinson's disease, which is the most common form of parkinsonism. The other conditions listed, such as rheumatoid arthritis, nonfunctioning gastrocnemius muscle, and muscular dystrophy, do not typically present with this specific symptom of difficulty in initiating gait.

Ataxic gait is the correct answer because it is characterized by a wide base of support and unsteady movements. This gait pattern is commonly seen in individuals with cerebellar dysfunction, which affects coordination and balance. The wide base of support is an attempt to compensate for the lack of coordination, while the unsteady movements result from the impaired control of muscle coordination. Parkinsonian gait, on the other hand, is characterized by small shuffling steps and a stooped posture. Scissor gait refers to a pattern where the legs cross over each other while walking, and antalgic gait is characterized by a shortened stance phase on the affected side due to pain.

In the optimal lateral view standing posture, a plumb line should be aligned with various landmarks to ensure proper alignment of the body. These landmarks include the earlobe, the acromion process of the shoulder, and the lateral view of the hip, knee, and ankle. However, the great toe is not included in this alignment. Therefore, the plumb line should not pass through the great toe in the optimal lateral view standing posture.

The correct answer suggests that the typical gait pattern seen in a patient who has had a stroke is a weight shift to the uninvolved side with circumduction of the involved leg. This means that the patient will lean towards the unaffected side and swing their affected leg outwards in a circular motion while walking. This gait pattern is commonly seen in stroke patients due to weakness or paralysis on one side of the body, leading to compensatory movements during walking.

A force couple refers to two forces that are equal in magnitude but opposite in direction and result in a turning effect. This means that the forces create a rotational motion without any translational motion. The forces in a force couple do not cancel each other out, but rather work together to produce a rotational force. This concept is often used in engineering and physics to describe systems that involve torque or moments.

The purpose of arm swing in gait is to provide a counterrotation effect of the trunk. This means that as the arms swing in the opposite direction to the legs, it helps to stabilize and balance the body during walking or running. The counterrotation effect of the trunk helps to reduce rotational forces on the spine and pelvis, allowing for a more efficient and coordinated movement.

During the swing phase, the person with a long leg cast that allows weight bearing is likely to circumduct the left hip. This means that they will swing their leg out to the side in a circular motion in order to move the limb forward. This compensatory movement is necessary due to the restricted mobility caused by the cast, allowing them to clear the ground and continue walking.

The pressure on the vertebral discs is greatest in the seated position. When sitting, the weight of the upper body is concentrated on the discs, leading to increased pressure. This is because the spine is not fully supported in a seated position, causing the discs to bear the majority of the load. In contrast, in the supine, side-lying, or standing upright positions, the weight is distributed more evenly across the spine, resulting in less pressure on the discs.

A fixed pulley is a type of machine that consists of a grooved wheel that turns on an axle with a rope or cable. Unlike a moveable pulley, a fixed pulley does not move along with the load being lifted. Instead, it is attached to a fixed point, such as a ceiling or a beam. When force is applied to one end of the rope, the fixed pulley allows for the load to be lifted or lowered with less effort. Therefore, a fixed pulley is the correct answer in this case.

The cervical and lumbar curves are considered to be the secondary (antigravity) curves. The cervical curve is located in the neck region and helps to maintain balance and support the weight of the head. The lumbar curve is located in the lower back and helps to support the weight of the upper body and distribute it evenly to the lower limbs. These curves play an important role in maintaining an upright posture and allowing for efficient movement and stability.

Neutral equilibrium refers to a state in which an object's center of gravity (COG) remains unchanged when it is disturbed. This means that the object will return to its original position after the disturbance. In neutral equilibrium, the object's COG is located at its lowest point, ensuring stability and balance. Unlike stable equilibrium, where the object's COG is lowered when disturbed, or unstable equilibrium, where the COG is raised, neutral equilibrium does not require any external force to maintain its position.

A person with a facet joint problem in the spine is generally most comfortable in the side-lying position with both legs flexed toward the chest. This position helps to relieve pressure on the facet joints by allowing the spine to be in a more neutral position. By flexing the legs towards the chest, it also helps to further reduce the load on the spine and decrease any potential discomfort. This position provides support and alignment to the spine, allowing for increased comfort and reduced pain.

A person with a lumbar disc problem is generally most comfortable lying prone because this position helps to relieve pressure on the lumbar discs. Lying prone allows the spine to be in a neutral position, reducing strain on the discs and promoting proper alignment. This position also helps to elongate the spine and can provide relief from pain and discomfort associated with lumbar disc problems.

Postural sway refers to the slight movement or swaying of the body that occurs when maintaining an upright posture. It is largely controlled by gravity and the muscles involved in maintaining balance. Ankle plantar flexion and dorsiflexion are the movements of the ankle that play a crucial role in maintaining balance and stability. Plantar flexion refers to pointing the toes downwards, while dorsiflexion refers to pulling the toes upwards towards the shin. These movements are controlled by the muscles in the lower leg, such as the calf muscles (gastrocnemius and soleus) and the muscles in the front of the leg (tibialis anterior). Therefore, ankle plantar flexion and dorsiflexion are important muscle groups involved in controlling postural sway.