Biomechanics of Joints, Planes, Palpation, and Clinical Assessment - Lecture Notes

Joints, Planes, Palpation, and Clinical Assessment (Lecture Transcript)

• Abduction vs Adduction (definitions and naming conventions)

  • Abduction: movement away from the midline or spreading apart (e.g., toes or fingers when they splay apart).
  • Adduction: movement toward the midline (e.g., bringing toes/fingers together).
  • The instructor notes that ligaments are named in terms of ulna/radius rather than medial/lateral, and emphasizes how abduction/adduction relate to the digits and joints.
  • Important nuance from the lecture: abduction of the toes when spread out; adduction when they are squished together. (Standard anatomy defines abduction as away from midline and adduction as toward midline.)

• Group number three: joints that rotate

  • Internal rotation and external rotation occur at:
  • the shoulder (glenohumeral joint) and the hip (coxal joint);
  • the wrists (radiocarpal complex);
  • the cervical spine (often called spinal rotation in lecture context).
  • Additional rotating joints discussed:
  • At the knee: when the knee is bent, the tibia can rotate on the femur (tibiofemoral rotation in flexion).
  • When the knee is straight (extended) and the foot is rotated, the rotation is actually occurring at the hip.
  • The elbow has a perfect rotary joint at the proximal radioulnar joint (pronation/supination).
  • Summary: rotation can occur across multiple joints, with specific conditions (knee flexed vs extended) changing which joint is doing the rotation.

• Group four: the only joint with plantar flexion and dorsiflexion

  • The ankle/foot is the sole joint complex that performs plantar flexion and dorsiflexion.

• Group five: supination and pronation

  • Supination/pronation are primarily described in the forearm (radius and ulna) when the hand is in anatomical position (supinated) vs palm facing down (pronated).
  • The lecture notes that the hands in the anatomical position are supinated, and when the palm rotates down (elbow often flexed), that’s pronation.
  • The same concepts apply to the foot: a runner may have a supinated foot (high arch) or a pronated foot (flat foot).
  • Key statement: supination occurs in the ankle/foot, midfoot, and forearm; pronation occurs similarly in those regions depending on the joint complex.

• Palpation and patient positioning (clinical palpation basics)

  • Patient positions commonly used for palpation:
  • Supine (on back), prone (on stomach), sideline (lateral recumbent, left or right), and Fowler’s position (semi-upright on a table).
  • Hook lying position: hips and knees bent with feet flat on the table (often used for palpation or assessment baseline).
  • Rationale for palpation in clinical assessment:
  • Palpation helps identify tenderness, swelling, warmth, scars, adhesions, and structural abnormalities.
  • Reference structures are used to orient palpation (e.g., acromion process for shoulder, patella for knee, malleolus for ankle).
  • Scar tissue can become adherent; push on the scar and observe whether adjacent skin and tissue move as normal. Adhesions can limit range of motion.
  • Important touch ethics:
  • Always ask permission before touching a patient and explain what you are going to do. Clear communication builds comfort and confidence.

• Regions and anatomical terms

  • Terms starting with gluteal/gluteus indicate buttocks region.
  • hallux = big toe; e.g., flexor hallux longus = muscle that flexes the big toe.
  • Mastery of terminology (e.g., hallux, gluteus, acromion process, malleolus) makes identifying structures easier.
  • Flashcards are recommended to memorize terms and locations for rapid identification in clinical settings.
  • Quick reference example (from the discussion): cervical region corresponds to the neck.

• Planes of motion

  • Sagittal plane: divides the body left and right halves; commonly used to describe flexion and extension movements.
  • Frontal (coronal) plane: divides the body into anterior and posterior portions; associated with abduction/adduction movements.
  • Transverse plane: divides the body into superior and inferior portions; associated with rotation.
  • Axis of rotation is always perpendicular to the plane of motion.
  • Example from lecture: movements in the sagittal plane include shoulder flexion; frontal plane movements include hip/knee abduction/adduction; rotation occurs in the transverse plane.

• Abdominal quadrants (clinical palpation and examination)

  • Upper Right Quadrant (URQ): liver and right kidney (the right kidney is partially obscured by the liver in the diagram).
  • Upper Left Quadrant (ULQ): stomach; spleen is also in this region and is clinically significant due to risk of rupture and substantial bleeding.
  • Lower Right Quadrant (LRQ): appendix (appendicitis is a common issue in young patients). The appendix is located in the lower abdomen and a common test is to palpate for tenderness in this region.
  • Lower Left Quadrant (LLQ): ovaries (in females) and testes (in males).
  • Note on spleen: rupture can lead to rapid bleeding; shoulder pain (left) can be referred pain due to splenic irritation.

• Clinical assessment framework (history, observation, palpation, ROM, tests, imaging)

  • History: a good history can give about 70% of the diagnostic picture. It should address which part is injured, mechanism, and prior injuries to other limbs for comparison (avoid assuming “normal laxity” on one side).
  • Pain description and quantification: use patient descriptors and a numeric scale, e.g., a 1–10 scale, to track improvement or worsening. Use a two-way assessment to capture pain type (nerve pain vs swelling vs fracture pain).
  • Observation/inspection: monitor gait, weight bearing, posture, and how the patient protects an injured region. Deformities or abnormal postures may indicate fracture or dislocation.
  • Swelling and discoloration:
  • Immediate swelling with discoloration is strongly suggestive of fracture.
  • Swelling without discoloration is more typical of a ligament sprain.
  • Blood supply and bone marrow are sources of bleeding in fractures; this explains immediate swelling and potential edema.
  • Incision and healing (post-curgical evaluation): signs of infection include discharge, excessive redness, red streaks moving away from the incision, fever, and increasing pain. Normal postoperative swelling/redness should gradually improve as healing progresses.
  • Anticipated changes with immobilization and rehab:
  • Expect atrophy in the immobilized limb (calf circumference, etc.).
  • By 48–72 hours, muscle atrophy can begin; with continued immobilization, you may sustain notable loss. Moving the limb can help preserve muscle mass; complete immobilization can lead to accelerated atrophy.
  • Palpation-focused assessment:
  • Determine tenderness, temperature, and texture; identify any structural deviations or deformities.
  • Palpate reference structures first (e.g., acromion for shoulder, patella for knee, malleolus for ankle) to guide subsequent palpation.
  • Temperature assessment: use the back of the hand for temperature sensitivity (the palm may pick up extraneous warmth from other sources).
  • Examine scar tissue and mobility around incisions (adherent scar tissue reduces range of motion and can require specific treatment like scar massage).
  • Safety and consent in hands-on examination:
  • Always obtain consent and explain each step, ensuring the patient understands what you’re about to do and why.

• Range of Motion (ROM) assessments

  • Passive ROM: clinician moves the joint with the patient relaxed; typically yields the largest ROM since muscle tension is minimized.
  • Active ROM: patient moves the joint on their own; compares with the contralateral side to assess function and pain limits.
  • Resisted ROM: tests strength by providing resistance to the patient’s movement.
  • Practical order and safety:
  • In acute injuries, begin with active ROM to avoid provoking further injury; if the patient cannot move, you cannot safely perform ROM testing.
  • In general, passive ROM often yields the greatest range, but you start with active ROM to assess safety and patient tolerance.

• Special tests and diagnostic testing on field vs clinic

  • Special tests (e.g., Lachman’s test for ACL integrity) help diagnose ligamentous injuries and laxity.
  • Field setting priorities:
  • Evaluate severity quickly to determine whether to move the patient off the field safely and whether splinting or other on-field care is necessary.
  • If a fracture or severe injury is suspected, prioritize fracture assessment and immobilization before other tests.
  • Imaging modalities for diagnosis:
  • X-ray: excellent for detecting fractures; can be named by view (AP, lateral, etc.). Not good for soft tissue alone.
  • MRI: superior imaging of soft tissue and swelling; performed in transverse or sagittal planes; sensitive but requires the patient to be still; claustrophobia or metal implants can be limiting factors.
  • CT: cross-sectional imaging with good bone detail; often preferred when rapid imaging is needed or if MRI is unsuitable; may use contrast dye.
  • Ultrasound: useful for soft tissue assessment and real-time evaluation; increasingly used in PT clinics and athletic training settings.
  • Specific ACL assessment note (Lachman’s test): forward translation of the tibia relative to the femur indicates potential ACL tearing; on-field tests help gauge severity before swelling develops.
  • General clinical rule: the first principle of evaluation is "+first do no harm"; the goal is to determine severity and plan safe patient removal from the field.

• Imaging specifics and considerations

  • X-ray projections are named by direction (AP = Anterior-Posterior; lateral; etc.).
  • MRI advantages: excellent soft tissue detail; can detect swelling and ligamentous injuries; magnetic field requires metal-free environment.
  • CT advantages: accessible, wide bore than MRI, often faster; good bone detail; dye-based CT angiography adds vascular information.
  • Ultrasound advantages: portable, safe for soft tissue and some bone assessment; used for diagnosis in some clinics beyond therapy.
  • Practical note: some patients cannot have MRIs due to metal implants or claustrophobia; CT may be a better option in those cases.

• Practical takeaways for exam prep and real-world relevance

  • Terminology mastery is crucial (e.g., hallux, acromion, malleolus, gluteal/gluteus, etc.).
  • Understanding planes and axes helps explain why certain movements occur in specific planes.
  • Recognize the signs of acute fractures vs sprains (swelling with discoloration vs swelling alone).
  • Know the sequencing of assessment (history → observation → palpation → ROM → special tests → imaging) and when to modify based on safety and severity.
  • Appreciate the on-field vs clinical decision-making: protect the patient first, then diagnose.

• Quick study tips mentioned in the session

  • Create flashcards for anatomical terms and regional locations to facilitate quick identification during exams.
  • Practice identifying quadrants and their typical organ or structure associations.
  • Use a 1–10 pain scale and describe pain characteristics to distinguish injury types.
  • Review the relation between runners’ foot mechanics (supination vs pronation) and arch height as a practical real-world relevance.

• Summary of key formulas and figures mentioned

  • Pain scale: $1 ext{ to } 10$
  • Muscle atrophy timeline: $48 ext{ to } 72 ext{ hours}$ to begin noticeable atrophy when immobilized; movement extends preservation (approx. two weeks with mild continued use).
  • Imaging descriptors: AP, lateral views for X-rays; transverse/sagittal slices for MRI; wide bore vs narrow bore for MRI claustrophobia considerations.

• Final exam-oriented checklist (condensed)

  • Define and distinguish abduction/adduction and their application to toes/fingers.
  • List joints capable of internal/external rotation and the conditions under which rotation is performed (e.g., knee flexion vs extension).
  • Identify the only joint with plantar flexion/dorsiflexion (ankle/foot) and the joints involved in supination/pronation.
  • Memorize major palpation reference points (acromion, patella, malleolus) and the rationale for their use.
  • Differentiate sagittal, frontal, and transverse planes and their associated movements; relate to axis of rotation.
  • Explain the four abdominal quadrants and the primary organs in each.
  • Describe the sequence of clinical assessment (history → observation → palpation → ROM → special tests → imaging) and safety considerations on the field.
  • Understand indications for imaging modalities (X-ray for bone, MRI for soft tissue, CT with contrast, ultrasound for soft tissue) and practical constraints (claustrophobia, metal implants).