NATA-BOC MCQ 2 — Questions and Answers
Question 1: Which muscle is the primary agonist during hip flexion?
- Rectus femoris
- Iliopsoas (Correct answer)
- Sartorius
- Tensor fasciae latae
Correct answer: Iliopsoas
The iliopsoas (composed of the psoas major and iliacus) is the strongest and primary hip flexor. While the rectus femoris, sartorius, and TFL all assist with hip flexion, the iliopsoas is the dominant agonist.
The iliopsoas is composed of the psoas major (originating from T12-L5 vertebral bodies and transverse processes) and the iliacus (originating from the iliac fossa). They merge to insert on the lesser trochanter of the femur. The iliopsoas is the most powerful hip flexor and is active during walking, running, and sit-ups. The rectus femoris is a two-joint muscle that assists hip flexion but primarily extends the knee. The sartorius is the longest muscle in the body and assists hip flexion, abduction, and external rotation. The TFL assists hip flexion and internal rotation but is a weaker contributor.
Question 2: What is the normal resting heart rate range for a healthy adult?
- 40-60 bpm
- 60-100 bpm (Correct answer)
- 80-120 bpm
- 100-140 bpm
Correct answer: 60-100 bpm
The normal resting heart rate for a healthy adult is 60-100 beats per minute. Well-conditioned athletes may have resting heart rates below 60 bpm (sinus bradycardia), which is a normal adaptation to aerobic training.
The American Heart Association defines normal resting heart rate as 60-100 bpm for adults. Heart rates below 60 bpm (bradycardia) can be normal in highly trained endurance athletes due to increased stroke volume and vagal tone. Heart rates consistently above 100 bpm at rest (tachycardia) may indicate dehydration, fever, anemia, thyroid dysfunction, or cardiac conditions. Athletic trainers should establish baseline resting heart rates for their athletes and monitor for significant changes. Factors affecting resting heart rate include: fitness level, medications, caffeine, emotional state, body position, and environmental temperature. Resting heart rate is best measured first thing in the morning before getting out of bed.
Question 3: The rotator cuff is composed of four muscles. Which of the following is NOT a rotator cuff muscle?
- Supraspinatus
- Infraspinatus
- Teres major (Correct answer)
- Subscapularis
Correct answer: Teres major
The rotator cuff consists of the supraspinatus, infraspinatus, teres minor, and subscapularis (SITS muscles). The teres major is NOT part of the rotator cuff; it is a separate muscle that assists with shoulder extension, adduction, and internal rotation.
The four rotator cuff muscles (SITS) work together to dynamically stabilize the glenohumeral joint by compressing the humeral head into the glenoid fossa: Supraspinatus — initiates abduction (first 15 degrees), most commonly injured; Infraspinatus — primary external rotator; Teres minor — assists external rotation; Subscapularis — primary internal rotator, largest rotator cuff muscle. The teres major originates from the inferior angle of the scapula and inserts on the medial lip of the bicipital groove, functioning as a shoulder extensor, adductor, and internal rotator. It is sometimes called 'the latissimus dorsi's little helper' because it assists the latissimus dorsi with these movements.
Question 4: During a preparticipation physical examination, an athletic trainer measures an athlete's blood pressure at 152/96 mmHg. How should this reading be classified?
- Normal
- Elevated
- Stage 1 hypertension
- Stage 2 hypertension (Correct answer)
Correct answer: Stage 2 hypertension
According to the American Heart Association guidelines, Stage 2 hypertension is defined as systolic blood pressure of 140 mmHg or higher, or diastolic blood pressure of 90 mmHg or higher. A reading of 152/96 exceeds both thresholds.
The AHA/ACC blood pressure classification system: Normal — less than 120/80 mmHg; Elevated — systolic 120-129 and diastolic less than 80; Stage 1 Hypertension — systolic 130-139 OR diastolic 80-89; Stage 2 Hypertension — systolic 140+ OR diastolic 90+; Hypertensive Crisis — systolic over 180 and/or diastolic over 120. A reading of 152/96 is Stage 2 because both values exceed their respective thresholds (systolic 140+, diastolic 90+). This reading should be confirmed on a separate occasion before diagnosis. The athletic trainer should refer the athlete to their primary care physician for further evaluation. Proper measurement technique is essential: seated quietly for 5 minutes, arm supported at heart level, appropriate cuff size.
Question 5: Which type of muscle contraction occurs when the muscle lengthens while producing force?
- Concentric
- Eccentric (Correct answer)
- Isometric
- Isokinetic
Correct answer: Eccentric
An eccentric contraction occurs when a muscle generates force while lengthening. This occurs during deceleration movements, such as lowering a weight or the braking phase of running. Eccentric contractions produce more force than concentric contractions.
There are three primary types of muscle contractions: Concentric — muscle shortens while producing force (lifting a dumbbell during biceps curl); Eccentric — muscle lengthens while producing force (lowering the dumbbell, descending stairs, decelerating during running); Isometric — muscle produces force without changing length (holding a weight at a fixed position, wall sits). Eccentric contractions are significant in athletic training because they can produce approximately 20-50% more force than concentric contractions, they are responsible for most exercise-induced muscle damage (DOMS), and eccentric training is a key component of tendinopathy rehabilitation (eccentric decline squats for patellar tendinopathy, eccentric heel drops for Achilles tendinopathy). Isokinetic refers to constant velocity movement, typically measured with a dynamometer.
Question 6: An athletic trainer is assessing cranial nerve function. Which cranial nerve is being tested when the athlete is asked to shrug their shoulders against resistance?
- CN VII (Facial)
- CN X (Vagus)
- CN XI (Accessory) (Correct answer)
- CN XII (Hypoglossal)
Correct answer: CN XI (Accessory)
Cranial nerve XI (Spinal Accessory) innervates the sternocleidomastoid and trapezius muscles. Testing shoulder shrug against resistance assesses trapezius function and therefore CN XI integrity.
Cranial nerve XI (Spinal Accessory) has a spinal root that ascends through the foramen magnum and exits through the jugular foramen. It innervates two muscles: the sternocleidomastoid (tested by resisted head rotation) and the trapezius (tested by resisted shoulder shrug). Testing both muscles provides a comprehensive CN XI assessment. CN VII (Facial) controls facial expression muscles; CN X (Vagus) controls palatal elevation, vocal cord function, and parasympathetic visceral functions; CN XII (Hypoglossal) controls tongue movement. Cranial nerve testing is important in head injury assessment to identify potential brainstem or peripheral nerve involvement. Athletic trainers should be proficient in assessing all 12 cranial nerves as part of neurological screening.
NATA-BOC MCQ 2
Which muscle is the primary agonist during hip flexion?