Stanbridge - T4 - W4 - Knee

Objectives of Knee Examination and Testing

• Review bones, joints, ligaments, and musculature of the knee
• Learn range of motion measurements for the knee using goniometry
• Learn Manual Muscle Test (MMT) positions for knee musculature against gravity
• Review dermatomes on and near the knee
• Discuss appropriateness of range of motion and manual muscle testing
• Document goniometry and strength testing in the objective section of notes
• Review normal and abnormal end feels and discuss capsular patterns of the knee

Anterior, Medial, and Posterior Views of the Right Knee

• Review the anterior, medial, and posterior anatomy of the right knee joint

Superior View of the Right Knee

• Review the superior view of the right knee including the ligaments, meniscus, and articular surfaces

Knee Goniometry: Flexion

• Normal knee flexion range occurs between 0-135 degrees
• The patient should be positioned supine
• The therapist should be positioned alongside the patient
• The fulcrum of the goniometer is placed on the lateral epicondyle of the femur
• The stationary arm aligns with the lateral midline of the femur, targeting the greater trochanter
• The movable arm aligns with the lateral midline of the fibula, targeting the lateral malleolus
• The normal end feel for knee flexion is soft tissue approximation

Knee Goniometry: Extension

• Normal knee extension is 10 degrees
• If the patient is supine, place a towel under the ankle
• The therapist should be positioned alongside the patient
• The fulcrum of the goniometer is placed on the lateral epicondyle of the femur
• The stationary arm aligns with the lateral midline of the femur, targeting the greater trochanter
• Movable arm: lateral midline of the fibula (lateral malleolus)
• The normal end feel is capsular/firm, indicating tension in the posterior joint capsule, oblique/arcuate popliteal ligaments, collateral ligaments, and cruciate ligaments

Principles of Range of Motion (ROM)

• Examples of Capsular Patterns
• Limitation of motion is restricted.

Tibiofemoral Range of Motion

• Flexion is more limited than extension, Flex > Ext

Knee Flexion Functional Range

• Walking on level surfaces requires 63.1 degrees of motion.
• Ascending stairs requires 92.9 degrees of motion.
• Descending stairs needs 86.9 degrees of motion.
• Rising from a chair requires 90.1 degrees of motion.
• Sitting in a chair requires 0-93.0 degrees of motion.
• Tying shoes needs 0-106.0 degrees of motion.

Manual Muscle Testing (MMT) Grading

• 0/5 Zero: No palpable muscle contraction occurs.
• 1/5 Trace: A palpable muscle contraction is present, but there is no joint movement.
• 2-/5 Poor Minus: There is a minimal range of motion in gravity eliminated position.
• 2/5 Poor: The complete range of motion is possible in gravity eliminated position.
• 2+/5 Poor Plus: There is partial range of motion against gravity or movement against slight resistance in gravity eliminated position.
• 3-/5 Fair Minus: Gradual release occurs from the test position.
• 3/5 Fair: The test position is held against gravity.
• 3+/5 Fair Plus: It includes the ability to hold test position against gravity with slight pressure.
• 4-/5 Good Minus: Able to hold the test position against gravity with slight to moderate pressure.
• 4/5 Good: Holding test position against gravity with moderate pressure is achievable.
• 4+/5 Good Plus: Holding test position against gravity with moderate to strong pressure can be achieved.
• 5/5 Normal: The test is held against gravity with strong pressure and is normal

Knee Extension: Muscles and Testing

• The quadriceps femoris is the primary muscle group for knee extension.
• The testing position against gravity involves seating the patient with the knee over the side of the table.
• Stabilization is achieved with the therapist's hand under the distal femur, and the patient holds the table.
• The movement involves almost full knee extension without locking or rotation.
• Resistance is applied on the distal Tibia and Fibula toward knee flexion.
• Weakness is indicated by decreased knee extension strength.
• If gravity is eliminated, the testing position becomes side-lying with the Lower Extremity (LE) supported.
• Potential compensations during testing include hip flexion and hip rotation.

Knee Flexion: Muscles and Testing

• The lateral hamstrings consist of the biceps femoris
• The medial hamstrings consist of the semitendinosus and semimembranosus.
• The testing position against gravity involves the patient being prone with the knee flexed to 50-70 and the hip in slight lateral rotation; the tibia in slight lateral rotation on the femur
• Stabilization achieved by holding testing the thigh firmly on table
• The movement being tested is knee flexion, with slight hip External Rotation (ER) and tibia slightly laterally rotated on the femur

Knee Flexion: Popliteus Testing

• The popliteus NWB medially rotates tibia on femur and flexes knee, WB laterally rotates the femur on tibia and flexes knee
• To test, position is seated with the knee flexed to 90 with lateral rotation of tibia on femur
• Stabilize by doing nothing
• Movement includes medial rotation of the tibia on femur
• Resistance: none
• Weakness causes a reduced ability to rotate lower leg

Muscle Length Measurements Around the Knee

• Ely's test measures rectus femoris length.
• The Prone Knee Bend assesses vasti muscle length.
• Hamstring length/popliteal angle

Ely's Test: Rectus Femoris Length Testing

• To take Ely's test, position the patient prone with feet off of the mat, and hips at 0 extension without a pillow
• The test involves stabilizing the patient's pelvis to keep the hip neutral and passively flexing the knee by applying pressure to the distal tibia and fibula
• The test causes resistance felt from anterior thigh tension (R1) and further knee flexion causes compensatory hip flexion (R2)

Additional Notes on Ely's Test

• A normal rectus femoris length has a knee flexed > or = to 90 degrees
• During the test, compare both sides
• R1 is first resistance.
• R2 is end resistance

Prone Knee Bend Test: Single Joint Quadriceps-Vasti Muscles

• Position: is same as Ely's but release is stabilization of pelvis, hip in flexion with a pillow under the hips
• Test: flex knee as with Ely's
• End test: when R2 is reached
• Normal vasti allows heel is to reach buttocks, compare bilaterally

Clinical interpretation of the Quadriceps Length Tests

• Positive Ely's Test and Positive Prone Knee Bend: tight quadriceps (one joint and two joint quads)
• Positive Ely's Test and Negative Prone Knee Bend: tight rectus femoris muscle
• Negative Ely's Test and Negative Prone Knee Bend: normal quadriceps length

Popliteal Angle Test: Hamstring Length

• Position: the patient is supine with the testing hip at 90 degrees flexion and neutral in frontal and transverse planes, the other leg flat on the table with knee extended fully
• Test: Stabilize femur on testing leg, slowly extend knee until end of ROM
• End: resistance is felt from tension in the posterior thigh causes hip to move towards extension (R2)
• Popliteal angle signifies = angle of thigh to leg or from vertical to lower leg (180 degrees - number)
• First Resistance: R1
• End Resistance: R2
• Adults: popliteal angle ≥160 signifies it is normal or Neg test O
• Children: popliteal angle ≥130° signifies it is normal or Neg test

Review: Thomas Test

• Check if the user recalls the result of this Thomas Test and make sure they are specific.

Quiz Question About Capsular Pattern

• What is the capsular pattern at the tibiofemoral joint?

Deep Sensation Testing

• Pressure Sensation
• Deep Pain Sensation
• Vibration Sensation
• Proprioception Sensation
• Kinesthetic Sensation

Deep Sensory Testing: Pressure

• Touch with fingertip uses firm, direct perpendicular pressure to stimulate deep receptors, without being painful
• Note if the patient feels anything.
• Randomly alternate the touch with vibration with and without vibration

Deep Sensory Testing: Deep Pain

• Apply firm pressure/squeeze to a muscle belly (forearm or calf).

Deep Sensory Testing: Vibration

• preferably, use a 128 Hz tuning fork
• Alternate randomly touch with vibration and without vibration
• Test over interphalangeal joint of finger or great toe
• If impairment, test bony prominences more proximally, (ex. humeral epicondyle, spinous process, patella, medial malleolus, anterior superior iliac spine)

Deep Sensory Testing: Proprioception

• Proprioception Testing: Perception of the body's position in space with joint/limb movement
• Hand placement needs to not hinder or assists patient
• Minimize cues other than the feeling of movement, one hand is proximal and lateral to the joint being moved, the moving hand is distal to the joint being moved

Deep Sensory Testing: Kinesthetic

• Perception of joint motion in space - mirroring movement/position
• The involved limb is put into a position, usually.
• The patient moves the uninvolved limb to match the same position: Hand placement is just proximal and lateral to the joint being moved.

Cortical Sensation Testing

• It includes these 6 tests:
  • 2-Point Discrimination Sensation
  • Stereognosis Sensation
  • Barognosis Sensation
  • Graphesthesia Sensation
  • Localization of Touch Sensation
  • Bilateral Simultaneous Stimulation Sensation
• Only perform this type of testing only if superficial and deep sensation is intact

Cortical Sensation Testing: 2-Point Discrimination

• There are specific devices available, if you do not have one, use a caliper or paper clip; open/measure the distance between the two ends
• Use the discriminator, caliper or paper clip, and touch with one/two of the testing tips at a time, in random order
• If pt is able to distinguish a feel of one/two touch
• Find the minimum distance at which patient is able to discriminate the two tips in different areas

Cortical Sensation Testing: Stereognosis

• Patient identifies an object without visual input, only by touch
• The objects have to be potentially not harmful
• Use coins, comb, pencil, key, or paperclip

Cortical Sensation Testing: Barognosis

• Barognosis: A patient perceives the varying weight differences without external input, Objects should be similar in shape and design but have differing weight

Cortical Sensation Testing: Graphesthesia

• Number or letter drawn with finger on patient's skin with blunt object, without visual input
• This is often performed as a palm test
• The client may be impaired if three misses are made

Cortical Sensation Testing: Localization of Touch

• Allows the patient to specify what section is lightly touched

Cortical Sensation Testing: Bilateral Simultaneous Stimulation

• Light touch to right or left limb in order
• The subject responds with their sensory perception
• The client expresses if same/diff in the regions
• An alternative is tactile extinction testing

Grading of Sensation

• Score of 0: Absent-- patient is unable to determine the test of sensation or cannot determine with touch

• Score of 1: Altered or impaired-- Patient has an altered or increased level of sensitivity; may increase the skin sensitivity

• Score of 2: Intact or normal - Correct responses to all of that test

• NT= Patient not tested- Can't establish a comparison of intact skin, patient not tolerating testing, or is not appropriate to test (document reason)

Deep Tendon Reflex Testing

• The tendon is stimulated when the muscle response is graded.

Patellar Reflex

• Tapping the patellar ligament stretches the quadriceps and gets excited
• Afferent impulses in the spinal cord
• If a pt has motor neuron or sensory lesions then reflexes will be abnormal.
• Synapses occur where motor neruons and interneurons are, the motor neuorns send activating stimuli to the quadriceps
• Interneurons make synapses
• Ventral neurons can inhibit antagonizing muscles from contracting

Deep Tendon Reflex Responses

• Lower Motor Neuron (LMN) lesion to peripheral nervous system: results in hypo-reflexive response
• Upper Motor Neuron (UMN) lesion to central nervous system: results in hyper-reflexive response

Common Deep Tendon Reflex (DTR Testing Sites)

• Biceps tendon levels C5-6
• Brachioradialis tendon or muscle belly: C5-6 level
• Triceps tendon at C6-7
• Pattelar tendon at levels L3-6. 
• Achilles tendon: S1-2

Deep Tendon Reflex Testing Procedures

• The patient should be completely relaxed
• Test will enable a better assessment of the DTR
• Always slightly stretch the muscle
• Use direct quick movements/strikes on joints

DTR Grading

• Grading 0= no response is always abnormal
• Grading 1+is defined as decreased/depressed and must be compared bilaterally to classify as abnormal.
• Grading 2+ is defined as active, normal response
• Grading 3+ is defined as exaggerated response
• Grading 4+ - Very brisk/hyperactive; usually indicative of a lesion in the brain

Therapeutic Measurement and Testing (TMT) of the Knee: Documentation

• Follow measurement guidelines and MMT
• Describe patient response of each test and notate any area of pain
• The Sensations are graded
• Sensation is graded as Intact, Poor, Fair, Good (subjective)
• 0 = absent; 1 = impaired; 2 = intact; NT= not tested