Joint Structure and Function: A Comprehensive Analysis 5th Edition Test Bank

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Chapter 1: Biomechanical Applications to Joint Structure and FunctionMultiple ChoiceIdentify the choice that best completes the statement or answers the question.____1.When you raise a cup to your mouth, a ____________________ of motion occurs at the elbowjoint.a.rotation onlyb.translation onlyc.translation and rotationd.None of the above answers are correct.____2.Hip abduction from an anatomic position would occur in which plane?a.Sagittalb.Frontalc.Transversed.Horizontal____3.Which of the following describes the phenomenon that when two forces come in contact, thesecond force will respond to the contact by the first force with equal magnitude and in the oppositedirection?a.Law of Inertiab.Law of Reactionc.Law of Accelerationd.None of the above answers are correct.____4.A ____________________ class lever is described by the fulcrum occurring at one end, followedby the resistance (load or weight) and then the force (effort).a.Firstb.Secondc.Thirdd.Fourth____5.In what type of lever is the M Ad always less than one?a.Firstb.Secondc.Thirdd.Fourth____6.Which of the followingbestdescribes torque?a.The force a muscle generatesb.A force times the perpendicular distance from the line of force to the axis ofrotationc.A force times the distance measured along the lever from the line of force to theaxis of rotationd.The distance a muscle can move

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Figure 1-7____7.In Figure 1-7, the biceps is acting on the forearm. What is theforceof the biceps,FB, given thefollowing: moment arm of the biceps,d= 0.02 m and torque due to the biceps,TM=–5 Nm?a.–0.1 Nb.1,250 Nc.5 Nd.–250 N____8.As your patient abducts her shoulder from 90° to 120°, the moment arm decreases. If the torquefrom the deltoidremains constant, the force of the deltoid would ____________________ as theshoulder abducted.a.remain the sameb.increasec.decreased.become 0 NFigure 1-9____9.In Figure 1-9, at which position does the weight have the greatest torque capabilities on the kneejoint?a.Ab.Bc.Cd.D

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____10.In Figure 1-9, at which position does the weight produce the greatest distractive on the knee joint?a.Ab.Bc.Cd.DFigure 1-11____11.Which of the following represents the magnitude of each of the two component forces of theresultant,FR,in Figure 1-11?a.F1= 86.6 N,F2= 50 Nb.F1= 50 N,F2= 60 Nc.F1= 10 N,F2= 90 Nd.F1= 20.6 N,F2= 79.4 N____12.Considering the figure below, which of the following answers best represents the direction of theresultant force?a.b.c.d.____13.Which of the following describes the phenomenon that causes a body moving at a constant speedto remain at that speed, unless it is acted upon by another body or force?a.Impulseb.Energy levelc.Law of Reactiond.Law of Inertia____14.Which of the following statements describes the relationship between joint reaction forces and thetranslational/rotatory component forces?a.The contact force and translation component force run parallel to each other.

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b.The contact force and rotatory component force run parallel to each other.c.The shear force and translation component force run parallel to each other.True/FalseIndicate whether the statement is true or false.____1.When the centers of mass (CoM) of two adjacent segments are combined, the combined CoM willbe located somewhere along a line connecting the two individual CoMs.____2.Therelativeline of gravity changes with changes in body position.____3.An eccentric muscle contraction is an example of a second-class lever system.Short Answer1.Is naming the plane of motion considered part of kinetics or kinematics? Why?2.What happens to the center of gravity (CoG) of the body when the body segments are rearranged?What happens to the CoG if the right upper extremity is amputated?3.A student is carrying all his books for his Fall semester courses (first year) in his right arm. Whatdoes the additional weight do to the combined center of gravity (CoG) of body and books? Howwill his body most likely respond to this change?4.Upon what variables is the magnitude of friction dependent?5.What kind of force system do the fibers within a muscle form? Explain.6.How do you determine the net effect of two muscle pulls applied to the same spot? What is thisprocess called?7.Explain how anatomical pulleys affect the magnitude and direction of a muscle force (Fms).8.If a force is applied at an angle to a lever (not 90°, not 0°), what is the process by which youdetermine the torque applied to the lever by that force?9.If a force is applied at an angle to a lever (not 90°, not 0°), what is the process by which youdetermine the torque applied to the lever by that force?10.If not all of a muscle’s force is contributing to rotation, what happens to the “wasted” force?Describe by resolution of forces.11.Using the values given in the following problem, determine whether the lever is in rotational orlinear (translatory) equilibrium.Fms = 50 lb. (rt. of axis)Wt = 10 lb. (rt. of axis)Fr = 15 lb.Wr = 6 lb. (clockwise)

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(counterclockwise)Ft = 40 lb. (toward jt)Wt = 6 lb. (away from joint)la = 1(rt. of jt)la = 12(rt. of jt)12.If you have a patient with a recent ligamentous injury to his knee, which of thefollowing positionswould you want to avoid and why: sitting, prone, supine, sitting with legs over the edge of the bed,or prone with knees flexed to 90°.

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Chapter 1: Biomechanical Applications to Joint Structure and FunctionAnswer SectionMULTIPLE CHOICE1.ANS:CRotatory and translatory motions in the human body most commonly occur together.PTS:12.ANS:BThe frontal (coronal) plane divides the body into front and back halves. Movements in this planeoccur side to side, such as the case in abduction of the hip.PTS:13.ANS:BPTS:14.ANS:BPTS:15.ANS:CA mechanical advantage occurs when the effort arm is greater than the resistance arm. This isalways the case in a third-class level if all forces are equal.PTS:16.ANS:BTorque equals force times distance. The distance must be represented by themoment armof theforce, not just the direct distance as measured up the lever. The moment arm is the perpendiculardistance of the line of the force from the axis of rotation.PTS:17.ANS:DBecauseT= (F) (MA) therefore,F=T/MA: (–)5 Nm/0.02 m = (–)250 N. The negative sign isused to show direction of the force. Due to the small moment arm, the force necessary to produce(–)5 Nm of torque is quite large.PTS:18.ANS:BIf the torque were to remain the same, the force would have to increase as the moment armdecreases. Force and moment arm have an inverse relationship if torque is to remain constant.PTS:19.ANS:DThe force of the weight did not change from position to position; therefore, position D would havethe greatest torque capabilities due to this position offering the largest moment arm of the weighton the lever.PTS:1

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10.ANS:AWhen the line of force is parallel with the moving segment, it will create either a distractive orcompressive force between the two boney segments. Distraction occurs when there is a pull ormovement of one bony segment away from another. Because the weight would be moving the tibiaaway from the femur, it will create a distractive force.PTS:111.ANS:ASin 60 = 0.866 multiplied by the force of 100 N = 86.6 N, and Cos 60 = 0.05 multiplied by theforce of 100 N = 50 N.PTS:112.ANS:CYou find the resultant pull of the two forces by drawing the two forces, creating a parallelogram byadding sides parallel to each of the forces, and drawing a diagonal within the parallelogram. Theresultant is the diagonal with its point of application at the original source and whose arrow head(limit of magnitude) is at the opposite corner of the parallelogram. This is called composition offorces.PTS:113.ANS:DNewton’s Law of Inertia addresses the conditions under which an object will be in equilibrium.PTS:114.ANS:AThe contact force runs perpendicular to the joint surface which is in the same plane as the lever.The translational force runs parallel with the lever; therefore, these two forces run parallel to eachother.PTS:1TRUE/FALSE1.ANS:TPTS:12.ANS:TThe human body can be considered as a single rigid object. Even though the center of gravity doesnot change base on position, the relative line of gravity will shift so that it remains verticallydownward.PTS:13.ANS:T

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In this case, the force of gravity would be considered the effort force, and the muscle resisting thisforce would be considered the resistance force. Because gravity typically acts at a distance fartherfrom the axis than does the pull of the muscle, this would mean that the force involved is acting onthe system as a second-class lever.PTS:1SHORT ANSWER1.ANS:Kinematics. It is purely a description of motion without regard to the forces causing it.PTS:12.ANS:(1) The CoG shifts in the direction(s) of the location of the segments with the greatest mass. (2)The CoG shifts down and to the left once the mass of the right arm is removed, because the lowerand left halves of the body are now relatively heavier.)PTS:13.ANS:The center of gravity (for body and books) will be higher and to the right of S2. Because this newlocation of the CoG would bring the line of gravity (LoG) to the right side of his base of support,he will lean to the left to bring the LoG back to the middle of the base of support (most stableplace). The shift in the CoG is unavoidable. The shift of the LoG is an automatic adaptation butunder some volitional control.PTS:14.ANS:The magnitude of friction is dependent upon (1) the magnitude of contact between the two surfaceson which the friction is occurring—increased contact increases the maximum value of staticfriction or the absolute value of kinetic friction; (2) the nature of the contacting surfaces—therougher one or both of the surfaces (increased coefficient of static or kinetic friction), the greater isthe maximum value of static friction or the absolute value of kinetic friction; and (3) the shearforce(s) on the objects—friction has magnitude only when there is attempted motion (staticfriction) or actual motion (kinetic friction) between the two surfaces—the magnitude of friction onastaticobject will always equal thenetshear force on that object; the magnitude of friction on amoving object is always the product of the contact force and the coefficient of kinetic friction.PTS:15.ANS:Concurrent. Each fiber represents a separate force vector with the same generalpoint ofapplication but which pulls at an angle to each other.PTS:16.ANS:

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You find the resultant pull of the two forces by drawing the two forces, creating a parallelogram byadding sides parallel to each of the forces, and drawing a diagonal within the parallelogram. Theresultant is the diagonal with its point of application at the original source and whose arrow head(limit of magnitude) is at the opposite corner of the parallelogram. This is called composition offorces.PTS:17.ANS:Anatomical pulleys (always single pulleys) do not affect the magnitude of Fms but do change thedirection of pull. The change in action line generally brings the action line away from the jointaxis, thus increasing the moment arm or rotatory component of the applied force.PTS:18.ANS:Resolve the force into its components, which are perpendicular (rotatory) and parallel (translatory)to the lever. Torque for the force is then determined by multiplying the magnitude of the rotatorycomponent by its distance (lever arm) from the joint axis.PTS:19.ANS:Resolve the force into its components that are perpendicular (rotatory) and parallel (translatory) tothe lever. Torque for the force is then determined by multiplying the magnitude of the rotatorycomponent by its distance (lever arm) from the joint axis.PTS:110.ANS:The “wasted” force goes toward translation. The translatory component (ft) is a force appliedparallel to the shaft of the bone, either toward the joint (compression or joint reaction force) oraway from the joint (distraction).PTS:111.ANS:In this instance, the lever is rotating clockwise with a magnitude of 57 in-lb. The lever is not inlinear equilibrium according to the information given. There is a net joint compression of 34 lb.PTS:112.ANS:Sitting with legs over the edge of the bed. In this position, gravity is parallel to the limb, creating afull distractive force. Because this is usually a position of relaxation for the muscles, the only forceto counteract the distraction of the limb weight is tension in the injured ligaments.PTS:1

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Chapter 2: Joint Structure and FunctionMultiple ChoiceIdentify the choice that best completes the statement or answers the question.____1.Which of the following statements is true concerning fibroblasts?a.They synthesize the extracellular matrix of connective tissue.b.They are not normally present in healthy connective tissue.c.They are undifferentiated precursor cells.d.They are circulating cells.____2.Which of the following statements is true concerning nutrition of articular cartilage?a.Articular cartilage can easily repair itself due to its very efficient and effectivenutritional system.b.Nutrients are found in large proportions in the more superficial layers of articularcartilage.c.Nutrients from synovial fluid can pass into articular cartilage when externalpressure is applied.d.All forms of joint loading will cause poor nutrition to articular cartilage.____3.Which of the following statements istrueconcerning articular cartilage injury?a.A superficial laceration is capable of healing itself by filling in with fibrovasculartissue.b.A deep cartilage lesion does not extend beyond the tidemark.c.A deep laceration may heal by forming new fibrocartilage.d.A superficial lesion is likely to heal faster than a deep one.____4.Which of the followingbestdescribes the structural composition of the extracellular matrix ofbone?a.Glycosaminoglycans, glycoproteins, water, and proteoglycansb.Collagen fibers, glycosaminoglycans, water, and mineralized bone saltsc.Collagen fibers, glycosaminoglycans, glycoproteins, water, proteoglycans, andmineralized bone saltsd.Glycosaminoglycans, glycoproteins, water, proteoglycans, and unmineralized bonesalts____5.Which of the following statements istrueconcerning the biomechanical properties of ligaments, ifthe rate of application of the force is increased?a.The ligament stores less energy to failure.b.The ligament requires more force to rupture.c.The ligament has decreased stiffness.d.The stiffness of the ligament is unchanged.

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Figure 2-6____6.For the stress-strain curve in Figure 2-6, identify the point of ultimate failure.a.Point Ab.Point Bc.Point Cd.Point DFigure 2-7____7.The plastic portion of the stress-strain curve pictured above lies between:a.Point A and point Bb.Point A and point Dc.Point B and point D____8.In Figure 2-7, point A can best be describes as:a.The point indicating the end of the elastic modulusb.The point where permanent deformation of the tissue begins to occurc.The point where “uncrimping” of the tissue endsd.The point where the greatest amount of force is being applied____9.As a clinician, you are attempting to produce permanent elongation in a severely contracted flexordigitorum profundus tendon. Which of the following general strategies concerning treatment willbeleasteffective in achieving permanent lengthening of the tendon?a.Apply force slowly to decrease the stiffness of the tendon.b.Apply a short duration force, keeping the force in the elastic range.c.Apply enough force to cause microfailure of some fibers in the tendon.d.Use a splint that will apply a low load to the tendon (at the beginning of the elastic

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range) for 3 weeks.____10.When describing the biomechanical properties of cancellous and cortical bone, which of thefollowing statements is true?a.Cancellous bone is stiffer than cortical bone and can withstand less strain beforefailure.b.Cortical bone is stiffer than cancellous bone and can withstand less strain beforefailure.c.Cancellous bone is stiffer than cortical bone and can withstand more strain beforefailure.d.Cortical bone is stiffer than cancellous bone and can withstand more strain beforefailure.____11.When a bone is repeatedly loaded with low-level forces over an extended period of time, fatiguefractures may occur within the bone. This is due to:a.Increased stiffness, decreased yield strength, increased permanent deformationb.Decreased stiffness, increased yield strength, no effect on deformationc.Decreased stiffness, decreased yield strength, increased permanent deformationd.Increased stiffness, increased yield strength, no effect on deformation____12.Which of the following is true about the biomechanical properties of a ligament (or tendon) if thewidth of the ligament is doubled?a.Greater elongation before failureb.Less elongation before failurec.Increased strength before failured.Decreased strength before failure____13.Which of the following joints has two or more degrees of freedom of osteokinematic motion?a.Third proximal interphalangeal (PIP) jointb.Superior radioulnar jointc.Radiocarpal jointd.Humeroulnar joint____14.Which of the following would constitute a closed kinematic chain activity of the left shouldercomplex?a.Using your left arm to push yourself out of a chairb.Throwing a Frisbee with your left handc.Combing your hair with your left handd.Waving with your left hand____15.Which of the following statements is true concerning “joint play” of a joint?a.Joint play is not considered a “normal” motion at the joint.b.They must be tested by application of an external force.c.They can be performed voluntarily by a subject.d.They occur only in the close-packed position of the joint.

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____16.A man is sitting on a chair. He brings himself up into a standing position. His tibiofemoral jointmoves from a flexed position to full extension during the maneuver. Which of the following bestdescribes what is happening at the tibiofemoral joint during this maneuver? Think in anatomicalterms.a.Anterior glide of the proximal tibia on the distal femurb.Posterior glide of the proximal tibia on the distal femurc.Anterior glide of the distal femur on the proximal tibiad.Posterior glide of the distal femur on the proximal tibia____17.Which of the following statements is true concerning the close-packed position of any joint?a.Capsular structures are loose.b.Ligaments around the joint are slack.c.The joint is relatively easy to separate with distraction.d.There is a maximum area of surface contact occurring.____18.Cartilage primarily receives its nutrition from ____________________.a.its high level of permeabilityb.diffusionc.a process of joint loading and unloading____19.Which of the following statements istrueregarding articular cartilage injury?a.A deep cartilage lesion does not extend beyond the tidemark.b.A deep laceration may heal by forming new fibrocartilage.c.A superficial lesion is likely to heal faster than a deep one.d.A cartilage injury cannot heal.____20.Increasing the rate of application of a force causes a ligament to ____________________.a.store less energy to failureb.require more force to rupturec.decrease stiffnessd.elongate more____21.To increase a patient’s wrist extension range of motion by using an accessory motion glidingtechnique, the therapist would want to perform a(n) ____________________.a.posterior glide of the carpals on the radiusb.anterior glide of the carpals on the radiusc.anterior glide of the radius on the carpalsShort Answer1.Describe the arrangement of fibers in hyaline cartilage. Why is this arrangement suited to itsfunction?2.Describe what happens when cartilage undergoes compression. What are the factors that determinethe response, and how does each factor affect it?3.What are the characteristics of viscoelasticity, and which of the following tissues exhibitsviscoelasticity: ligaments, tendons, hyaline cartilage, fibrocartilage, or bone?

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4.Define stress and strain.5.Define modulus of elasticity, stiffness, brittleness, and ductility.6.How is the synovial fluid within a joint formed? Of what is it composed?7.Define the motions of spin, slide, and roll as they relate to intra-articular joint motions? Which ismost common within a joint?8.What is the general effect of immobilization on connective tissues? What are the implications forthese changes?9.What are the mechanisms by which overuse may affect connective tissues?10.Define the termshypermobilityandhypomobilityas each refers to human motion.

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Chapter 2: Joint Structure and FunctionAnswer SectionMULTIPLE CHOICE1.ANS:AConnective tissue is made of cells and extracellular matrix. Fibroblasts are a type of resident cellthat not only serves a role as the cellular component but actually synthesizes the extracellularmatrix in which the cells reside. Fibroblasts play a large role in the synthesis of collagen, which isthe fibrillar component of most extracellular matrixes.PTS:12.ANS:CArticular cartilage in adults is highly porous, but compression is necessary to allow for fluidmechanics, which will provide nutrition to the multiple layers of the structure. Articular cartilage isdevoid of blood vessels in adults, and a movement of fluids caused by intermittent compressionand rest to the cartilage allows nutrients to be carried from the deeper layers, closer to thesubchondral bone (where there is a blood supply), to the more superficial layers.PTS:13.ANS:CUnless an injury breaks through the uncalcified cartilage layer, known as the tidemark, it isunlikely that it will heal. If an injury breaks through this layer, it is likely that the blood supplyfrom the subchondral bone may play a role in forming new fibrocartilage in place of hyalinecartilage. This may lead to endochondral ossification over time, but it is the only opportunitycartilage has for self-repair.PTS:14.ANS:CEach extracellular matrix has a combination of fibers (collagen) and an interfibrillar component(proteoglycans and glycoproteins). The proteoglycans can further be broken down intopolysaccharide chains called glycosaminoglycans (GAGs). In addition to this normal combinationof components, bone contains mineralized bone salts (calcium and phosphate crystals), which givethis structure its hard surface.PTS:15.ANS:BAll viscoelastic tissues exhibit rate-dependent properties that cause a change in tissue behaviorbased on rate of application of a force. When viscoelastic materials are loaded rapidly, they exhibitgreater resistance to deformation than when loaded more slowly and require more force to failurethan when loaded more slowly.PTS:16.ANS:D

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