Prosthetics & Orthotics 1

A semi-rigid orthosis would be the ideal choice for a patient who requires both motion control and shock absorption. This type of orthosis provides a balance between rigidity and flexibility, allowing for controlled motion while still providing some level of shock absorption. A rigid orthosis would provide maximum motion control but may not offer sufficient shock absorption, while a soft orthosis would provide good shock absorption but may not provide enough motion control. Therefore, the semi-rigid orthosis would be the most suitable option in this case.

Functional foot orthoses can range from semi-rigid to rigid, meaning that they can vary in their level of stiffness and support. This allows for customization based on the individual's specific needs and foot conditions. Some individuals may require a more flexible orthotic to provide moderate support and cushioning, while others may benefit from a rigid orthotic that offers maximum stability and control. The range of options ensures that functional foot orthoses can be tailored to effectively address a wide range of foot and lower limb issues.

Polypropylene is commonly used in prefabricated AFOs because it is a lightweight and durable plastic material. It offers good flexibility and resistance to wear and tear, making it suitable for orthotic devices like AFOs. Polyethylene is another type of plastic commonly used in AFOs, but polypropylene is preferred due to its superior properties. Transpolyisoprene and polycapriolactone are not commonly used in AFOs and may not possess the necessary characteristics required for this application.

If you apply a dorsal force to the 1st met head and it doesn't move, it would be classified as hypomobile. This means that there is a restriction in the movement of the 1st met head and it is not able to move as freely as it should.

A callus on the 5th met head indicates a supinated foot because the 5th met head is located on the outer edge of the foot, and supination refers to the outward rolling of the foot during walking or running. This causes excess pressure on the outer edge of the foot, leading to the formation of a callus in that area. Therefore, if there is a callus on the 5th met head, it suggests that the foot is in a supinated position.

A lateral heel wedge is a type of orthotic device that is placed on the outer side of the shoe to provide support and stability. By elevating the lateral side of the foot, it helps to shift the weight towards the inside of the foot, causing the knee to move towards a valgus position. This can be beneficial for individuals who have medial compression, as it helps to alleviate the pressure on the inner side of the knee joint. Therefore, the statement that a lateral heel wedge would cause valgus at the knee and be good for someone with medial compression is true.

A straight last is better for a pronator because it provides more stability and support to the foot. Pronation is the natural inward rolling motion of the foot during walking or running, and it can lead to overpronation if not properly supported. A straight last shoe, with a straight shape from the heel to the toe, helps to align the foot and prevent excessive inward rolling. This type of shoe is designed to control pronation and provide the necessary support for pronators, making it a better choice for them.

The correct answer is that orthotic devices should provide total surface contact to the medial longitudinal arch and be dynamic. This means that the orthotic should cover the entire arch of the foot and should be able to move and adapt to the foot's movement during walking or running. This is important because the total contact and dynamic nature of the orthotic helps to distribute forces evenly across the foot, providing support and stability. It also allows for natural movement and helps to prevent excessive pronation or supination.

We use Newton's third law most when manufacturing orthotic devices. This law states that for every action, there is an equal and opposite reaction. In the context of orthotic devices, this means that the forces exerted by the device on the body are countered by equal and opposite forces exerted by the body on the device. This law is crucial in ensuring that the orthotic device provides the necessary support and stability to the body.

Elevating the heel on the shorter leg would be appropriate in this case. By elevating the heel, the height of the shorter leg can be increased, helping to correct the leg length difference. This can help improve balance and reduce any discomfort or issues caused by the leg length difference.

The theory of controlled motion by changing joint alignment is not a theory of the neuromuscular response. The other options, altered muscle activation, altered sensory input, and muscle response is changed, are all theories that explain how the neuromuscular system responds and adapts to different stimuli and conditions. However, controlled motion by changing joint alignment is not a commonly recognized theory in the field of neuromuscular response.

Leather is a material that can deform in the direction of stress, which means that it can change its shape when subjected to pressure or tension. This is one of the desirable qualities of leather, as it allows it to conform to the shape of the wearer or the object it is used on. Therefore, the statement "It doesn't deform in the direction of stress" is false.

The balance foot theory states that the foot must be in a neutral position, which means neither supination nor pronation, in order to maintain balance. This is true and aligns with the statement that "Neutral position is a position of neither supination or pronation." However, the statement that "FF and RF deformities do not affect alignment" is false. Deformities in the forefoot (FF) and rearfoot (RF) can indeed affect the alignment of the foot. Therefore, the given answer is correct.

A compensated rearfoot varus refers to a condition where the rearfoot is tilted inward or inverted. To address this issue, a rigid, medial post would be appropriate. A medial post is a supportive device placed on the inner side of the shoe to help correct the alignment of the foot. By using a rigid material, it provides stability and prevents excessive inward rolling of the foot. This helps to redistribute the forces during walking or running and promote proper foot alignment. A lateral post would not be suitable as it would further tilt the foot inward, exacerbating the varus. Soft posts may not provide enough support to correct the alignment effectively.

The correct answer is "The steeper the stress/strain curve, the more brittle the material." This statement is false because a steeper stress/strain curve indicates a more ductile material, not a more brittle one. Ductile materials can undergo significant deformation before breaking, while brittle materials tend to fracture without significant deformation. Therefore, a steeper stress/strain curve is associated with higher ductility, not brittleness.

Permanent orthotic devices do not last 5 years, on average.

Plastizote is a type of plastic that is classified as closed cell polyethylene foam. This type of foam is characterized by its closed cell structure, which means that the individual cells are sealed off from each other, resulting in a material that is resistant to water absorption and has excellent insulation properties. Plastizote is often used in applications where cushioning and impact resistance are required, such as in packaging, sports equipment, and medical devices.

The given statement states that if the degree of posting is greater than 12, the posting should be divided between the RF and FF. However, the question asks for the option that is NOT a rule to follow when posting. Therefore, the correct answer is "If > 12 degrees, divide posting between RF and FF" because it contradicts the rule of dividing the posting when the degree is greater than 12.

When a patient has excessive pronation during gait, it means that their foot rolls inward excessively, causing instability and potential pain. To address this issue, modifying the heel can help decrease pronation. Beveling the lateral heel involves creating a slanted edge on the outer side of the heel, which helps to encourage the foot to roll outward slightly during gait. This adjustment can help to correct the patient's pronation and promote a more stable and aligned gait pattern. Flaring the lateral or posterior heel would not directly address the issue of pronation and may not provide the desired corrective effect.

An accommodative orthosis is not primarily used to control movement but rather to provide support, relieve pressure, and protect a body part. It is designed to accommodate the shape and function of the body part it is intended for, such as a foot or hand. While it may have some effect on movement, its main purpose is to provide comfort and prevent further injury or damage.

Hypotonia is not a clinical application of creep. Creep is a phenomenon where tissues gradually deform under constant stress over time. In the context of clinical applications, creep is commonly used to treat conditions such as spasticity, joint contracture, and elongation. Spasticity refers to the involuntary muscle contractions that can be relieved through creep therapy. Joint contracture involves the permanent shortening of muscles and tendons, which can be counteracted by applying creep stress. Elongation, on the other hand, involves the gradual stretching of tissues to increase their length. However, hypotonia refers to low muscle tone and is not typically treated using creep therapy.

PPT, or Polypropylene Terephthalate, is commonly used as a topcover in various applications. It is a type of plastic that offers excellent strength, durability, and resistance to chemicals and heat. PPT is often used as a protective layer or cover due to its ability to withstand wear and tear, making it a suitable choice for applications where a strong and long-lasting topcover is required.

In a patient with an uncompensated forefoot varus, the appropriate option would be to provide a soft orthotic with a medial post. This is because a medial post helps to support and stabilize the foot, correcting the varus alignment. A soft orthotic is preferred in this case as it provides cushioning and comfort, while still offering the necessary support. Using a lateral post or a rigid orthotic may not effectively address the varus deformity and may cause discomfort or further alignment issues.

Hysteresis refers to the phenomenon where a material exhibits a lag or delay in its response to an applied force or stress. In the context of the given question, hysteresis is the correct answer because it describes the property of a material to return to its original shape more easily than it took for the original application of force or stress. This means that the material retains some memory of its previous shape and requires less energy to revert back to it. Creep, viscoelasticity, and malleability are not suitable explanations as they do not specifically address this property of easy return to original shape.

The correct answer states that in closed kinetic chain (CKC) pronation, the subtalar joint (STJ) undergoes calcaneal eversion and talar adduction/plantarflexion (PF). This means that during CKC pronation, the heel bone (calcaneus) moves towards the midline of the body (adduction) and the foot points downwards (plantarflexion). This is the correct statement concerning the subtalar joint.

At the midtarsal joint, the axes are parallel during pronation. This allows the foot to become mobile, meaning it has the ability to move and adapt to different surfaces and positions.

STJ neutral refers to subtalar joint neutral position, which is the position of the foot where there is neither overpronation nor supination. Pronation is the inward rolling of the foot during gait, so it makes sense that STJ neutral is not correlated with pronation. The other options, RCSP (rearfoot calcaneal stance position), SLS RCSP (single-leg stance rearfoot calcaneal stance position), tibial rotation, and navicular position, are all static measurements that can be influenced by pronation during gait.