Ch. 5 biomechanics of human skeletal articulations

Joint stability is affected by which of the following? a. shape of the articulating bones b. arrangement and size of ligaments c. area of contact between the bones d. all of the above

all of the above

The knee is an example of which type joint? a. amphiarthroses b. synovial c. fibrous d. synarthroses

synovial

Hinge joints have how many axes? a. 2 b. 3 c. 1 d. none

1

At 25 degrees of knee flexion (neutral is 0 degrees, i.e. at full extension), the knee is the ideal open packed position. Which of the following describe an open packed joint? a. Decreased joint congruency b. Increased laxity of joint c. Joint play is maximized d. All of the above

All of the above

Where are Golgi tendon organs located? a. as part of the SEC (series elastic component) b. in the junctions between muscles and their tendons c. interspersed throughout the fibers of muscles d. Both A and B. e. A, B and C.

Both A and B.

Describe one type of PNF stretching.

One type of PNF stretching is the contract-relax-antagonist-contract technique. It is also known as the slow-reversal-hold-relax technique. It involves passive static stretch of the hamstrings by a partner, followed by active contraction of the hamstrings against the partner's resistance. After that, the hamstrings are relaxed and the quadriceps are contracted as the partner pushes the leg into increasing flexion at the hip. Then there is a phase of complete relaxation where the leg is held in the new position of increased hip flexion. Each phase of this process is held for 5 to 10 seconds and the entire sequence is carried out at lest four times.

List and describe four different joint injuries or pathologies.

The first joint injury is a sprain. A sprain is caused by abnormal displacement or twisting of the articulating bones that results in stretching or tearing of ligaments, tendons, and connective tissues crossing a joint. Sprains can occur at any joint but are most common at the ankle. Sprains can be classified as first, second, and third degree, depending on the severity of the injury. A second joint injury that can happen is a dislocation. A dislocation is the displacement of the articulating bones at a joint. These injuries result from falls or other mishaps involving a large magnitude of force. Common places for dislocations are the shoulders, fingers, knees, elbows, and the jaw. The symptoms include visible joint deformity, intense pain, swelling, numbness, and loss of joint movement capability. A third joint injury is bursitis, which is inflammation of a bursa. The bursae are sacs filled with fluid that function to cushion points where muscles or tendons slide over bone. Movement around the affected area becomes painful. The more the movement increases, the more the inflammation and aggravation increase. They are caused by overuse-type, repetitive minor impacts on the area, or from acute injuries. The fourth example is rheumatoid arthritis. It is the most debilitating and painful form of arthritis. It is an autoimmune disorder that involves the body's immune system attacking healthy tissues. Characteristics include inflammation and thickening of the synovial membranes and breakdown of the articular cartilage. This results in limitation of motion.

The term "hypermobile" is used to describe what? a. a gymnast b. a sprinter c. a joint with an unusually small range of motion d. a joint with an unusually large range of motion

a joint with an unusually large range of motion

he technique of proprioceptive neuromuscular facilitation (PNF) is based on responses elicited from which of the following? a. golgi tendon organs (GTO) b. muscle spindles c. both A and B d. neither A nor B

a. golgi tendon organs (GTO)

A triaxial joint allows which of the following movements? a. flexion and extension b. abduction and adduction c. rotation and circumduction d. all of the above

all of the above

Describe the different types of stretching exercises used to increase flexibility, including the advantages and disadvantages of each.

The five types of stretching are active, passive, ballistic, static, and dynamic. Active stretching is the stretching of muscles, tendons, and ligaments produced by active development of tension in the antagonist muscles. An advantage of active stretching is the exercising of muscle groups used to develop force. A disadvantage is limited ROM. Passive stretching is stretching of muscles, tendons, and ligaments produced by a stretching forced other than tension in the antagonist muscles. An advantage is movement is carried farther than the ROM that is present with active stretching, but there is the disadvantage of increased injury potential.Ballistic stretching is a series of quick, bouncing-type stretches. The use of body momentum is used to repeatedly extend joint position or to exceed the ROM. A disadvantage is the risk of micro-tearing of stretched muscle tissue because of activation of the stretch reflex and immediate development of tension. Another disadvantage is the potential for injury to all stretch tissues is increased because the extent of the stretch is not controlled. An advantage is that there is no transient decrease in muscle strength as there is in static stretching. Static stretching is maintaining a slow, controlled, sustained stretch over time, usually for over 30 seconds. For an optimal effect, the static stretch of each muscle group should be subsequentially repeated three to five. Disadvantages of static stretching is that there is a detrimental effect on muscle strength with a single, 30-s bought of static stretching. This can lead to reduction in performance in sprinting and endurance running events. The advantages of static stretching is that it is more effective in increasing joint range of motion. Dynamic stretching is a stretch that involves controlled, rather than bouncing motion. An advantage is that it is beneficial for activities that require muscular power, so it may be desirable to include it in a warm-up prior to an athletic competition. A disadvantage is that it can induce soreness in muscles that are not habitually stretched.

Describe the different types of synovial joints including movement and stability implications.

The six different types of synovial joints are gliding, hinge, pivot, condyloid, saddle, and ball and sockeet. Gliding joints are when the articulating bone surfaces in these joints are nearly flat, and the only movement is nonaxial gliding. Examples are the intermetatarsal, intercarpal, and intertarsal joints, and the facet joints of the vertebrae. Hinge joints have one articulating bone surface is convex while the other is concave. The strong collateral ligaments keep movement to a planar, hingelike motion. Examples are ulnohumeral and interphalangeal joints. Pivot joints have rotation that is permitted around one axis. Examples are the atlantoaxial joint and the proximal and distal radioulnar joints. Condyloid joints have one articulating bone surface is an ovular convex shape and the other is an ovular concave surface. Types of movement are flexion, extension, abduction, adduction, and circumduction. Saddle joints have both articulating bone surfaces are shaped like a riding saddle. Movement is extension, abduction, adduction, and circumduction, but with greater range that that of the condyloid joints. An example is the carpometacarpal joint of the thumb. Lastly, ball and socket joints have surfaces that are reciprocally convex and concave. Rotation in all three planes is permitted. Examples are hip and shoulder joints.

Explain the factors that contribute to joint stability.

The three factors that contribute to joint stability are the shape of the articulating bone surfaces, arrangement of ligaments and muscles, and other connective tissues. The first is the shape of articulating bone surfaces. Bone surfaces are exact opposites. One end is convex and the other is concave so that they can fit tightly together. A position in where the contact between the articulating bone surfaces is maximum is called a close-packed position. Another position is a loose-packed position. This is any join position other than the close-packed. The second factor is the arrangement. Tensions in ligaments and muscles help hold articulating bone ends together. These tissues can become weak from disuse or lax from being overstretched. This would lead to the reduction of joint stability. Also, the angle of which tendons are attached to bones is so that when the muscles exerts tensions, the articulating end of the bones at the joint crossed are pulled together; enhancing joint stability.

Range of motion at a joint is influenced by which of the following? a. shape of the articulating surfaces b. relative laxity and extensibility of the muscles crossing the joint c. fluid content of the cartilage within the joint d. all of the above

all of the above

Which of the following activates the muscle spindles? a. knee-jerk test b. ballistic stretching c. PNF stretching d. all of the above

all of the above

Which of the following contain synovial fluid? a. bursae b. tendon sheaths c. articular cartilage d. both A and B e. all of the above

all of the above

Which of the following is associated with triaxial joints? a. ball and socket b. 3 axes c. hip d. all of the above

all of the above

Which of the following is true regarding bursitis? a. overuse injury b. frictional irritation in one or more bursae c. inflammation d. both A and B e. all of the above

all of the above

Which of the following is/are characteristic(s) of bursae? a. They are associated with synovial joints. b. They separate tendons from bones to reduce friction. c. They separate skin from bones to reduce friction. d. both A and B e. all of the above

all of the above

Which of the following joint injuries is accompanied by inflammation? a. sprains b. dislocations c. bursitis d. all of the above

all of the above

Which of the following may increase the risk of injury? a. low levels of flexibility b. hyperflexibility c. high levels of joint laxity d. all of the above

all of the above

Which statement(s) is/are true? a. Exercise can increase the size and strength of tendons b. Exercise can increase the size and strength of ligaments. c. Exercise can increase the strength of tendon junction with a bone. d. all of the above

all of the above

Which of the following does not affect the range of motion at a joint? a. the degree of tonus of surrounding muscles and ligaments b. the shape of the articular surfaces c. the exercise habits of the individual d. the temperature of the surrounding tissue e. all of the above affect joint ROM

all of the above affect joint ROM

Which of the following are characteristics of diarthrodial joints? a. Articulating bone surfaces are covered with articular cartilage. b. An articular capsule surrounds the joint. c. They are lubricated by synovial fluid. d. all of the above.

all of the above.

A series of quick, bouncing-type stretches is called ______________ stretching.

ballistic

Golgi tendon organs respond in which of the following ways? a. inhibit tension (contraction) in the activated muscle b. initiate tension (contraction) in the antagonist muscle c. both A and B d. none of the above

both A and B

What characteristics do tendons and ligaments share with muscles? a. extensibility b. extensibility c. contractility d. both A and B e. all of the above

both A and B

Which of the following are examples of articular fibrocartilage? a. the intervertebral discs b. the menisci of the knee c. both A and B d. none of the above

both A and B

Which of the following are functions of articular cartilage? a. minimize friction and wear at a joint b. protect against joint dislocation c. both A and B d. neither A nor B

both A and B

Which of the following is/are characteristic(s) of tendon sheaths? a. They are synovial structures. b. They surround tendons. c. both A and B d. none of the above

both A and B

Which of the following is/are true regarding amphiarthrodial joints? a. Hyaline cartilage holds the bones together. b. They are slightly moveable. c. both A and B d. neither A nor B

both A and B

Which of the following statements is/are true? a. The hip is more stable than the shoulder. b. The shoulder has more range of motion than the hip. c. both A and B d. none of the above

both A and B

What is the result when a ligament is stretched beyond its elastic limit? a. A sprain occurs. b. Joint stability may be temporarily compromised. c. all of the above d. Joint stability may be permanently compromised. e. both A and B

c. all of the above

Which of the following is an example of a uniaxial joint? a. hip b. carpals c. elbow d. base of thumb

elbow

The degree to which an articulation (where two bones meet) is allowed to move before being restricted by surrounding tissues (ligaments/tendons/muscles etc.)... otherwise known as the range of uninhibited movement around a joint: a. joint proprioception b. joint mobility c. joint stability d. joint flexibility

joint mobility

A goniometer is used to directly measure what? a. muscle flexibility b. joint range of motion c. joint stability d. none of the above

joint range of motion

The "ability of a joint to resist abnormal displacement" defines what? a. joint flexibility b. joint mobility c. joint stability d. loose-packed position

joint stability

_______________ connect bone to bone

ligaments

The articular fibrocartilage partial disc in the knee is called __________________.

meniscus

The stretch reflex, or myotatic reflex, is provoked by activation of which of the following in a stretched muscle? a. muscle spindles b. Golgi tendon organs c. both A and B d. neither A nor B

muscle spindles

Which type(s) of arthritis is/are non-inflammatory? a. rheumatoid arthritis b. osteoarthritis c. both A and B d. none of the above (both A and B are inflammatory)

osteoarthritis

Which of the following refers to the stretching of muscles, tendons, and ligaments by a force other than tension in the antagonist muscles? a. active stretching b. passive stretching c. ballistic stretching d. none of the above

passive stretching

Which type of stretching demonstrates greater range of motion? a. active stretching b. passive stretching c. A and B are equal d. need more information

passive stretching

The carpometacarpal joint at the base of the thumb is an example of a ______________ joint.

saddle

The myotatic reflex, also known as ______________ reflex, is provoked by the activation of the muscle spindles in a stretched muscle.

stretch

Which connective tissue attaches muscle to bone? a. ligaments b. tendons c. both A and B d. none of the above

tendons

_________________ connect muscle to bone.

tendons

Which of the following is not associated with synarthrodial joints? a. typically weak b. sutures of the skull c. immovable d. fibrous

typically weak

Which of the following terms does not fit with the others? a. carpals b. short bones c. gliding movements d. uniaxial

uniaxial