I. Signs: Upper motor neuron lesion findings

  1. Muscle group weakness (not complete paralysis)
  2. Minimal muscle atrophy
  3. "Clasp-knife" spasticity
    1. Initial resistance to motion is strongest
    2. Once initial resistance gives-way, resistance to motion is less for remaining range of motion
  4. Hyperreflexia with or without Clonus
  5. Babinski reflex positive response
  6. Pathologic spread of reflexes
    1. Muscle contractions produce motions in muscles other than the one tested
  7. Precaution
    1. Cauda equina are all peripheral nerves
    2. Upper motor neuron findings for levels below T12 or L1 must be central lesions in the higher cord
      1. Strongly consider severe Cervical Spinal Stenosis
  8. Reference
    1. Robbins (2012) Board Review Express, San Jose

II. Exam: Muscle Strength Grading

  1. Grade 0: Total Paralysis
  2. Grade 1: Palpable or visible contraction
  3. Grade 2: Full range of motion with gravity eliminated
  4. Grade 3: Full range of motion against gravity
  5. Grade 4: Full range of motion with decreased strength
  6. Grade 5: Normal Strength
  7. NT: Not testable

III. Exam: Common Motor deficits

  1. Ulnar Nerve: Claw Hand
  2. Radial Nerve: Wrist drop
  3. Median Nerve: Cannot make 'OK' Sign
  4. Peroneal Nerve: Foot drop

IV. Exam: Higher Cervical Cord

  1. C2: Breathing
  2. C3-4: Spontaneous breathing, Trapezius function
  3. C4-6: Shoulder Flexion, Extension

V. Exam: Upper Extremity Strength

  1. C5: Deltoid Abduction at Shoulder
  2. C6: Biceps Flexion at Forearm
  3. C6: Wrist Extension (extensor carpi radialis)
  4. C7: Wrist Flexion
  5. C7: Elbow Extension (Triceps)
  6. C7: Finger Extension
  7. C8: Fingers Flexion middle finger (flex dig profundus)
  8. T1: Small finger abductors (abductor digiti minimi)
  9. T1: Interossei - Spread Fingers

VI. Exam: Lower Extremity Strength

  1. L2-3: Hip flexors (Iliopsoas)
  2. L3-4: Knee Extension (Quadriceps)
  3. L4: Ankle dorsiflexion (tibialis anterior)
  4. L4: Anterior Tibial - Foot Inversion
  5. L5: Great toe extension (Extensor hallucis longus)
  6. L5: Foot dorsiflexion (Extensor digitorum longus)
  7. L5: Weak heel walking, foot drop
  8. S1: Ankle plantar flexors (Gastrocnemius, Soleus)
  9. S1: Toe walking
  10. S1: Foot Eversion

Images: Related links to external sites (from Google)

Ontology: Structure of myotome (C0231043)

Concepts Embryonic Structure (T018)
SnomedCT 5898009
English Myotome, NOS, myotome, myotomes, Myotome, Structure of myotome (body structure), Structure of myotome
Spanish estructura del miótomo (estructura corporal), estructura del miótomo, miótomo

Ontology: Motor testing (C0430740)

Concepts Diagnostic Procedure (T060)
SnomedCT 141998009, 164837008, 34118006
English Motor testing, NOS, Musculo-skeletal test NOS, Musculo-skeletal test NOS (procedure), motor test, motor tests, motor testing, Locomotor test, Motor testing (procedure), Motor testing
Spanish Musculo-skeletal test NOS, examen motor (procedimiento), examen motor, prueba musculoesquelética, SAI, prueba para el sistema musculoesquelético, SAI (procedimiento), prueba para el sistema musculoesquelético, SAI

Ontology: Motor nerve (C0501384)

Definition (FMA) General anatomical term applied to nerves in which somatic efferent nerve fibers predominate.
Concepts Body Part, Organ, or Organ Component (T023)
English Motor nerve, Nervus motorius, motor nerves, motor nerve, nerve motor

Ontology: Muscle Strength (C0517349)

Definition (CSP) force exerted by a muscle, as a response parameter (e.g. bioassay) or as an indicator of health, endurance, fitness, etc.
Definition (MSH) The amount of force generated by MUSCLE CONTRACTION. Muscle strength can be measured during isometric, isotonic, or isokinetic contraction, either manually or using a device such as a MUSCLE STRENGTH DYNAMOMETER.
Concepts Organ or Tissue Function (T042)
MSH D053580
English Muscle strength, Muscle Strength, Strength, Muscle, strength muscle, muscle strengthing, muscle strength
Portuguese Força Muscular
Spanish Fuerza Muscular
Russian МЫШЦЫ СИЛА, МЫШЕЧНАЯ СИЛА, MYSHTSY SILA, MYSHECHNAIA SILA
Italian Forza muscolare
Finnish Lihasvoima
Czech svaly - síla, svalová síla
Polish Siła mięśni, Wytrzymałość mięśni
French Force du muscle, Force musculaire
Swedish Muskelstyrka
German Muskelkraft

Ontology: Motor root (C2339332)

Concepts Classification (T185)
English Motor root