Mobilization Convex-Concave Rule PDF

Musculoskeletal Basics 43 Example: stance phase of gait Open kinetic chain (OKC) Distal segment is not fixed and moves freely Example: swing phase of gait Figure 10. Open and Clo...

Musculoskeletal Basics 43 Example: stance phase of gait Open kinetic chain (OKC) Distal segment is not fixed and moves freely Example: swing phase of gait Figure 10. Open and Closed Kinematic Chain. Muscle Actions Types of muscle contractions Isometric: no change in muscle length Isotonic: change in muscle length while force or tension remains constant ➤ Concentric: muscle shortens when producing force ‡ Example: lifting yourself up against gravity (uphill running) ➤ Eccentric: muscle lengthens when producing force ‡ Example: lowering yourself against gravity (downhill running) Isokinetic: constant-velocity muscle action that requires special equipment ➤ Mnemonic: NIntendo ELiminates CoSts = Nothing Isometric, Eccentric Lengthens, Concentric Shortens Joint Motions Osteokinematics Movement between bones ➤ Osteo = bones ➤ Kinematics = study of motion Arthrokinematics Movement between joint surfaces ➤ Artho = joint ➤ Kinematics = study of motion Table 13. Joint Arthrokinematics. Motion Description Roll One joint surface rolling on another in a certain direction (cf tire rolling on road) Glide or slide Pure translatory motion of one surface gliding on another Takes place within the joint (cf braked wheels skidding) Spin Rotation of a movable component of a joint Note: Not commonly on the NPTE Book_5566_Ch03.indd 43 18-04-2024 22:05:54  44 NPTE Final Frontier – Mastering the NPTE Figure 11. Convex concave rule: A) Roll and Slide in opposite direction B) Roll and Slide in same direction. Concave–Convex Rule Describes the relationship between osteokinematics and arthrokinematics Concave Hollowed or rounded inward Concave on convex: glide occurs in the same direction ➤ If a moving surface is concave, the slide occurs in the same direction as the roll ➤ Mnemonic: concAve = sAme ➤ Example: elbow flexion ‡ Roll and slide are both occurring anteriorly ⚬ Ulna (concave) is moving on the humerus (convex) Convex Curved or rounded outward Convex on concave: glide occurs in the opposite direction ➤ If a moving surface is convex, the slide occurs in the opposite direction of the roll ➤ Mnemonic: cOnvex = Opposite ➤ Example: shoulder abduction ‡ Roll is occurring superiorly, whereas slide is occurring inferiorly ⚬ Humerus (convex) is moving on the glenoid fossa (concave) Thumb Mechanics The thumb is a saddle joint, so it has two different planes. Radial adduction (flexion) and radial abduction (extension) Concave on convex: distal concave moves on proximal convex (same direction) Radial adduction (flexion) = ulnar glide Radial abduction (extension) = radial glide Palmar adduction and palmar abduction Convex on concave: distal convex moves on proximal concave (opposite direction) palmar adduction = volar (anterior) glide palmar abduction = dorsal (posterior) glide Final Frontier’s Rule of Thumb: This is how we roll! When we think of the rolling of the 1st digit, your first digit is giving you the answers. ➤ As we go into first-digit flexion (FLX), the first digit is pointing to the ulnar side of your arm, telling you that it’s an ulnar roll. ➤ As we go into first-digit extension (EXT), the first digit is pointing to the radial side of your arm, telling you that it’s a radial roll. ‡ If you have trouble remembering which is first-digit EXT, think back to that anatomical snuff box. One must do first-digit EXT to get it to be prominent. ➤ As we go into first-digit abduction (ABD), the first digit is creating a “V” (first and second digits), telling you that it’s rolling volar. Book_5566_Ch03.indd 44 18-04-2024 22:05:55  Musculoskeletal Basics 45 ➤ As we go into first-digit adduction (ADD), the first digit is coming into your hanD (so you can slap this upcoming NPTE exam), telling you that it’s rolling dorsal. ➤ First-digit FLX and EXT are both concave on convex, so roll and slide (glide) are in the same direction. ➤ First-digit ABD and ADD are both convex on concave, so roll and slide (glide) are in opposite directions. Open and Closed Packed Positions Resting or loose-packed position Minimal surface contact and maximal joint play Perform joint mobilizations in this position Closed position Maximum surface contact and maximal tension Do not perform joint mobilizations in this position Range of Motion Limitations To determine which mobilization grade to perform for limited motion Grade I or II mobilizations: pain or muscle guarding present Grade III or IV mobilizations: no pain present Classification of grades Grade I: slow, small-amplitude motion at beginning of range Grade II: slow, large-amplitude motion within range but not reaching limit Grade III: slow, large-amplitude motion in middle to end of available range Grade IV: slow, small-amplitude motion at limit of available range and stressed into tissue resistance Grade V: high-velocity, small-amplitude thrust at limit of available range End Feels Table 14. Normal End Feels. End Feel Cause Hard Bone or cartilage Example: elbow extension Soft Soft tissue approximation Example: elbow flexion Firm Capsular and ligamentous stretching Example: shoulder flexion Table 15. Pathological End Feels. End Feel Cause Hard HO or other bony obstruction (in abnormal location) Boggy Edema, joint swelling Springy Meniscal displacement Rubbery Muscle spasm Firm with decreased elasticity Fibrosis of soft tissues Empty Muscle guarding or pain Hypermobile Too much motion Hypomobile Too little motion Abbreviation: HO, heterotropic ossification. Book_5566_Ch03.indd 45 18-04-2024 22:05:55