EMG Procedures & Techniques — Questions and Answers
Question 1: What is the primary purpose of a needle electrode in EMG testing?
- To deliver electric stimulation
- To draw blood samples
- To record muscle electrical signals (Correct answer)
- To measure skin resistance
Correct answer: To record muscle electrical signals
Needle electrodes are inserted into muscles to record electrical activity and assess neuromuscular function.
Question 2: Why is patient positioning important during EMG testing?
- To reduce blood pressure
- To monitor brain activity
- To ensure accurate recordings and patient comfort (Correct answer)
- To measure vital signs
Correct answer: To ensure accurate recordings and patient comfort
Proper positioning ensures muscle relaxation or activation as needed and minimizes artifacts in EMG recordings.
Question 3: What does insertional activity refer to in an EMG procedure?
- Activity after muscle contraction
- Response to stimulation
- Initial electrical response upon needle insertion (Correct answer)
- Skin surface voltage
Correct answer: Initial electrical response upon needle insertion
Insertional activity is the brief burst of electrical activity seen when a needle electrode is inserted into a muscle.
Question 4: Which technique is used to evaluate nerve conduction velocity?
- Needle biopsy
- Skin impedance test
- Nerve conduction study (Correct answer)
- Reflex arc testing
Correct answer: Nerve conduction study
Surface electrodes stimulate and record nerve impulses at two points to calculate the speed of nerve conduction.
Question 5: What is the typical response of a healthy muscle at rest during EMG?
- High amplitude bursts
- Intermittent spikes
- Electrical silence (Correct answer)
- Regular tremor waves
Correct answer: Electrical silence
A healthy muscle at rest should exhibit electrical silence, indicating no abnormal spontaneous activity.
Question 6: Which step is critical before inserting the EMG needle electrode?
- Applying bandages
- Shaving the head
- Preparing the skin for cleanliness (Correct answer)
- Taking blood pressure
Correct answer: Preparing the skin for cleanliness
Skin preparation helps reduce impedance and prevents contamination during needle insertion.
EMG Procedures & Techniques
What is the primary purpose of a needle electrode in EMG testing?