COMSAE Phase 3 Form 115 Practice Exam
Complete 176-Question Bank with Verified
Answers & Detailed Rationales 2025–2026
Edition | Board Prep for COMLEX-USA
Level 3
Question 1
A 28-year-old female presents with chronic headaches. Physical exam reveals a
restricted cranial rhythmic impulse. Palpation of the sphenobasilar synchondrosis
(SBS) reveals that the base of the sphenoid moves superiorly while the base of the
occiput moves inferiorly. Which of the following is the most likely diagnosis?
A) Flexion dysfunction
B) Extension dysfunction
C) Superior vertical shear
D) Inferior vertical shear
E) Torsion
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: OMM/Cranial
Rationale: In a vertical shear, the sphenoid and occiput rotate in the same direction
about two transverse axes. A superior shear occurs when the base of the sphenoid
moves superiorly relative to the occiput. In flexion, both move superiorly; in
extension, both move inferiorly. In torsion, they rotate in opposite directions about
an anteroposterior axis .
Question 2
A 62-year-old male with a history of chronic smoking presents with a persistent
cough, weight loss, a drooping right eyelid, and a constricted right pupil. Chest X-
,ray reveals a mass in the apex of the right lung. Which of the following structures
is most likely compressed?
A) Recurrent laryngeal nerve
B) Phrenic nerve
C) Sympathetic chain (stellate ganglion)
D) Brachial plexus
E) Vagus nerve
Clinical Presentation: Internal Medicine/Pulmonology | COMSAE
Focus: Pancoast Tumor
Rationale: The presentation describes Horner syndrome (ptosis, miosis,
anhidrosis) caused by compression of the sympathetic chain/stellate ganglion at
T1. This is classic for a Pancoast tumor (superior sulcus tumor), typically non-
small cell lung cancer. Recurrent laryngeal nerve compression causes hoarseness.
Phrenic nerve compression causes diaphragmatic elevation.
Question 3
A 35-year-old male presents with chronic low back pain. During osteopathic
evaluation, you note a right anterior innominate rotation. Which of the following
findings is consistent with this diagnosis?
A) Right ASIS superior and posterior, right ischial tuberosity inferior
B) Right ASIS inferior and anterior, right ischial tuberosity superior
C) Left ASIS inferior and posterior, left ischial tuberosity inferior
D) Symmetric PSIS levels with the patient in a seated position
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Pelvis/Innominate
Rationale: In a right anterior innominate rotation, the ilium rotates anteriorly
relative to the sacrum. The ASIS moves inferior and anterior, while the ischial
tuberosity moves superior. This dysfunction is often associated with a shortened
ipsilateral hip flexor (iliopsoas). Anterior innominate → shortened iliopsoas;
Posterior innominate → shortened hamstrings.
,Question 4
A patient presents with acute shortness of breath and decreased breath sounds on
the right. You suspect a rib dysfunction. Which rib group is most likely associated
with sympathetic innervation affecting bronchial smooth muscle?
A) Ribs 1–2
B) Ribs 3–5
C) Ribs 6–10
D) Ribs 11–12
Clinical Presentation: Osteopathic Principles & Practice/Pulmonology
| COMSAE Focus: Viscerosomatic Reflex
Rationale: Ribs 3–5 correspond to the sympathetics from T2–T6, which innervate
the lungs and bronchi. Rib raising in this area is used to treat increased sympathetic
tone in conditions such as asthma or bronchitis. The sympathetic chain ganglia lie
along the heads of the ribs, and somatic dysfunction in this region can contribute to
bronchospasm.
Question 5
According to Fryette's Laws, which of the following describes Type I (Neutral)
mechanics?
A) A group of vertebrae are rotated opposite to side bending in a neutral
position
B) A single vertebra is rotated to the same side as side bending
C) Only occurs in non-neutral positions
D) The facets are locked in flexion
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Fryette's Laws
Rationale: Fryette's Type I mechanics describe motion in the neutral position (no
flexion or extension). When a group of vertebrae sidebends, they rotate to
the opposite side. This pattern typically involves multiple vertebral segments and
, is often seen in scoliosis. Type II mechanics (non-neutral) involve a single vertebra
rotating to the same side as side bending.
Question 6
A patient presents with chronic constipation. You diagnose a somatic dysfunction
at the L5–S1 segment. Which parasympathetic innervation is likely affected?
A) Vagus nerve (CN X)
B) Pelvic splanchnic nerves (S2–S4)
C) Thoracolumbar outflow (T5–T9)
D) Superior mesenteric ganglion
Clinical Presentation: Osteopathic Principles & Practice/Gastroenterology
| COMSAE Focus: Autonomic Innervation
Rationale: The descending colon, sigmoid colon, and rectum receive
parasympathetic innervation from the pelvic splanchnic nerves (S2–S4) . Somatic
dysfunction in the lumbar or sacral region can impair this reflex arc, leading to
constipation. The vagus nerve supplies parasympathetic fibers to the proximal
colon only. High-yield: "Vagus to the splenic flexure; pelvic splanchnics the rest."
Question 7
During a Chapman's reflex examination, you palpate an area of fine crepitus in the
intercostal space at the 2nd rib on the right, near the sternum. This is most likely
associated with which organ?
A) Gallbladder
B) Stomach
C) Heart
D) Appendix
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Chapman's Points
Complete 176-Question Bank with Verified
Answers & Detailed Rationales 2025–2026
Edition | Board Prep for COMLEX-USA
Level 3
Question 1
A 28-year-old female presents with chronic headaches. Physical exam reveals a
restricted cranial rhythmic impulse. Palpation of the sphenobasilar synchondrosis
(SBS) reveals that the base of the sphenoid moves superiorly while the base of the
occiput moves inferiorly. Which of the following is the most likely diagnosis?
A) Flexion dysfunction
B) Extension dysfunction
C) Superior vertical shear
D) Inferior vertical shear
E) Torsion
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: OMM/Cranial
Rationale: In a vertical shear, the sphenoid and occiput rotate in the same direction
about two transverse axes. A superior shear occurs when the base of the sphenoid
moves superiorly relative to the occiput. In flexion, both move superiorly; in
extension, both move inferiorly. In torsion, they rotate in opposite directions about
an anteroposterior axis .
Question 2
A 62-year-old male with a history of chronic smoking presents with a persistent
cough, weight loss, a drooping right eyelid, and a constricted right pupil. Chest X-
,ray reveals a mass in the apex of the right lung. Which of the following structures
is most likely compressed?
A) Recurrent laryngeal nerve
B) Phrenic nerve
C) Sympathetic chain (stellate ganglion)
D) Brachial plexus
E) Vagus nerve
Clinical Presentation: Internal Medicine/Pulmonology | COMSAE
Focus: Pancoast Tumor
Rationale: The presentation describes Horner syndrome (ptosis, miosis,
anhidrosis) caused by compression of the sympathetic chain/stellate ganglion at
T1. This is classic for a Pancoast tumor (superior sulcus tumor), typically non-
small cell lung cancer. Recurrent laryngeal nerve compression causes hoarseness.
Phrenic nerve compression causes diaphragmatic elevation.
Question 3
A 35-year-old male presents with chronic low back pain. During osteopathic
evaluation, you note a right anterior innominate rotation. Which of the following
findings is consistent with this diagnosis?
A) Right ASIS superior and posterior, right ischial tuberosity inferior
B) Right ASIS inferior and anterior, right ischial tuberosity superior
C) Left ASIS inferior and posterior, left ischial tuberosity inferior
D) Symmetric PSIS levels with the patient in a seated position
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Pelvis/Innominate
Rationale: In a right anterior innominate rotation, the ilium rotates anteriorly
relative to the sacrum. The ASIS moves inferior and anterior, while the ischial
tuberosity moves superior. This dysfunction is often associated with a shortened
ipsilateral hip flexor (iliopsoas). Anterior innominate → shortened iliopsoas;
Posterior innominate → shortened hamstrings.
,Question 4
A patient presents with acute shortness of breath and decreased breath sounds on
the right. You suspect a rib dysfunction. Which rib group is most likely associated
with sympathetic innervation affecting bronchial smooth muscle?
A) Ribs 1–2
B) Ribs 3–5
C) Ribs 6–10
D) Ribs 11–12
Clinical Presentation: Osteopathic Principles & Practice/Pulmonology
| COMSAE Focus: Viscerosomatic Reflex
Rationale: Ribs 3–5 correspond to the sympathetics from T2–T6, which innervate
the lungs and bronchi. Rib raising in this area is used to treat increased sympathetic
tone in conditions such as asthma or bronchitis. The sympathetic chain ganglia lie
along the heads of the ribs, and somatic dysfunction in this region can contribute to
bronchospasm.
Question 5
According to Fryette's Laws, which of the following describes Type I (Neutral)
mechanics?
A) A group of vertebrae are rotated opposite to side bending in a neutral
position
B) A single vertebra is rotated to the same side as side bending
C) Only occurs in non-neutral positions
D) The facets are locked in flexion
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Fryette's Laws
Rationale: Fryette's Type I mechanics describe motion in the neutral position (no
flexion or extension). When a group of vertebrae sidebends, they rotate to
the opposite side. This pattern typically involves multiple vertebral segments and
, is often seen in scoliosis. Type II mechanics (non-neutral) involve a single vertebra
rotating to the same side as side bending.
Question 6
A patient presents with chronic constipation. You diagnose a somatic dysfunction
at the L5–S1 segment. Which parasympathetic innervation is likely affected?
A) Vagus nerve (CN X)
B) Pelvic splanchnic nerves (S2–S4)
C) Thoracolumbar outflow (T5–T9)
D) Superior mesenteric ganglion
Clinical Presentation: Osteopathic Principles & Practice/Gastroenterology
| COMSAE Focus: Autonomic Innervation
Rationale: The descending colon, sigmoid colon, and rectum receive
parasympathetic innervation from the pelvic splanchnic nerves (S2–S4) . Somatic
dysfunction in the lumbar or sacral region can impair this reflex arc, leading to
constipation. The vagus nerve supplies parasympathetic fibers to the proximal
colon only. High-yield: "Vagus to the splenic flexure; pelvic splanchnics the rest."
Question 7
During a Chapman's reflex examination, you palpate an area of fine crepitus in the
intercostal space at the 2nd rib on the right, near the sternum. This is most likely
associated with which organ?
A) Gallbladder
B) Stomach
C) Heart
D) Appendix
Clinical Presentation: Osteopathic Principles & Practice | COMSAE
Focus: Chapman's Points
