1. Electromyography (EMG) is used to measure:
(A) Muscle strength
(B) Muscle electrical activity
(C) Joint motion
(D) Bone density
2. Which type of EMG involves inserting a needle into the muscle?
(A) Surface EMG
(B) Intramuscular EMG
(C) Dynamic EMG
(D) Static EMG
3. Surface EMG electrodes are usually placed:
(A) On the skin over the muscle belly
(B) On tendons
(C) On bones
(D) Inside the joint
4. The main disadvantage of surface EMG is:
(A) High cost
(B) Invasiveness
(C) Signal cross-talk from nearby muscles
(D) Poor portability
5. Force plates are primarily used to measure:
(A) Muscle contraction
(B) Ground reaction forces
(C) Joint angle
(D) Bone alignment
6. Which component of motion is most directly captured by force plates?
(A) Kinematics
(B) Kinetics
(C) Electromyography
(D) Postural sway only
7. Motion capture systems primarily measure:
(A) Muscle activity
(B) Joint motion and body segment movement
(C) Ground reaction forces
(D) Nerve conduction
8. In optical motion capture, reflective markers are tracked by:
(A) Force plates
(B) Cameras
(C) EMG sensors
(D) Ultrasound probes
9. A typical sampling frequency for EMG analysis is:
(A) 5–10 Hz
(B) 50–100 Hz
(C) 500–2000 Hz
(D) 10,000 Hz
10. Which parameter is derived from force plate data?
(A) Muscle activation
(B) Center of pressure
(C) Muscle cross-sectional area
(D) Nerve conduction velocity
11. The latency between EMG activity and muscle force production is called:
(A) Force lag
(B) Electromechanical delay
(C) Action potential delay
(D) Reaction time
12. Which motion capture system uses magnetic fields to track movement?
(A) Optical system
(B) Electromagnetic system
(C) Inertial system
(D) Ultrasound system
13. A major limitation of electromagnetic motion capture is:
(A) Cost
(B) Sensitivity to metal interference
(C) Low accuracy
(D) High invasiveness
14. Inertial motion capture uses:
(A) Cameras
(B) Reflective markers
(C) Accelerometers and gyroscopes
(D) Force plates
15. Which type of EMG provides the most selective measurement of a single muscle fiber?
(A) Surface EMG
(B) Intramuscular EMG
(C) Wireless EMG
(D) High-density EMG
16. The main advantage of wireless EMG systems is:
(A) Lower cost
(B) No signal processing required
(C) Greater subject mobility
(D) Higher invasiveness
17. Force plates can measure forces in how many dimensions?
(A) 1
(B) 2
(C) 3
(D) 6 (3 forces + 3 moments)
18. In gait analysis, force plate data is synchronized with:
(A) EMG only
(B) Motion capture
(C) X-rays
(D) MRI scans
19. Which system provides the most detailed 3D motion reconstruction?
(A) Optical motion capture
(B) Surface EMG
(C) Force plates
(D) Ultrasound
20. Which factor most affects EMG signal quality?
(A) Skin impedance
(B) Joint angle
(C) Force plate calibration
(D) Camera resolution
21. Motion capture markers are typically placed on:
(A) Ligaments
(B) Anatomical landmarks
(C) Muscle fibers
(D) Nerve pathways
22. Which type of analysis combines EMG, force plates, and motion capture?
(A) Neurological testing
(B) Full biomechanical gait analysis
(C) Radiographic analysis
(D) Anthropometry
23. The ground reaction force vector passes through the:
(A) Center of mass
(B) Center of pressure
(C) Hip joint
(D) Muscle belly
24. A force plate typically measures:
(A) Only vertical force
(B) Vertical, anterior-posterior, and medial-lateral forces
(C) Only horizontal forces
(D) Electromyographic activity
25. In motion capture, a higher frame rate is needed for:
(A) Slow movements
(B) Fast movements
(C) Static posture
(D) Balance testing
26. High-density EMG uses:
(A) A single electrode
(B) Multiple closely spaced electrodes
(C) Needle electrodes only
(D) Inertial sensors
27. Which of the following is a drawback of optical motion capture?
(A) Skin movement artifact
(B) Metal interference
(C) Electrode cross-talk
(D) Noisy ground reaction force
28. EMG amplitude is commonly normalized to:
(A) Resting muscle activity
(B) Maximum voluntary contraction (MVC)
(C) Force plate output
(D) Center of mass
29. Which type of force plate is portable and commonly used in sports biomechanics?
(A) Laboratory-grade multi-axis plates
(B) Instrumented treadmill
(C) Portable force platforms
(D) EMG-integrated plates
30. Motion capture combined with EMG helps in identifying:
(A) Neural conduction delays
(B) Muscle activation timing relative to movement
(C) Bone density changes
(D) Blood circulation patterns
31. Which sensor measures angular velocity in inertial systems?
(A) Accelerometer
(B) Gyroscope
(C) Magnetometer
(D) Electrode
32. A force plate records a sharp peak at heel strike due to:
(A) Shock absorption
(B) Muscle fatigue
(C) EMG noise
(D) Poor calibration
33. The RMS value of an EMG signal represents:
(A) Frequency content
(B) Amplitude of muscle activity
(C) Joint torque
(D) Kinematic displacement
34. Which markerless motion capture technology is becoming popular in biomechanics?
(A) Infrared camera-based
(B) MRI-based
(C) AI-based video tracking
(D) X-ray-based
35. Which step is essential before applying surface EMG electrodes?
(A) Joint lubrication
(B) Skin preparation (shaving/cleaning)
(C) MRI scan
(D) Bone palpation
36. Which force component is most relevant in vertical jump analysis?
(A) Mediolateral
(B) Vertical
(C) Anteroposterior
(D) Shear
37. Synchronization of EMG and motion capture is required to analyze:
(A) Heart rate variability
(B) Timing of muscle activation with movement phases
(C) Bone healing
(D) Static posture only
38. Inertial measurement units (IMUs) are advantageous because they are:
(A) Limited to lab use
(B) Small, wearable, and portable
(C) Invasive
(D) Restricted to joint angles only
39. The frequency range of most useful EMG signals is:
(A) 0–10 Hz
(B) 20–500 Hz
(C) 1–2000 Hz
(D) Above 5000 Hz
40. Which variable can be derived from both motion capture and force plate data?
(A) Joint moments
(B) Neural conduction velocity
(C) Muscle fiber length
(D) Bone mineral density
41. Which marker placement is used to measure knee kinematics in gait labs?
(A) ASIS, PSIS, lateral femoral condyle, lateral malleolus
(B) Tibialis anterior, soleus, gastrocnemius
(C) Sacrum, scapula, humerus
(D) Vertebrae and skull
42. Motion capture accuracy can be affected by:
(A) Light reflection and occlusion of markers
(B) Bone density
(C) Muscle cross-talk
(D) EMG filtering
43. Which variable cannot be directly measured by force plates?
(A) Center of pressure
(B) Joint torque
(C) Ground reaction forces
(D) Moments about plate axes
44. The most common artifact in surface EMG is caused by:
(A) Fatigue
(B) Skin movement
(C) Bone vibration
(D) Electrode detachment
45. Force plate data is essential for calculating:
(A) Net joint moments
(B) Resting EMG levels
(C) Maximum voluntary contraction
(D) Electrode impedance
46. The Nyquist theorem suggests EMG sampling rate should be at least:
(A) Twice the highest signal frequency
(B) Half the lowest signal frequency
(C) Equal to 100 Hz
(D) Independent of signal frequency
47. A pressure-sensitive walkway is an alternative to:
(A) EMG
(B) Force plate in gait analysis
(C) Optical motion capture
(D) Gyroscope sensors
48. Which of the following is a benefit of high-density EMG?
(A) Better spatial resolution of muscle activity
(B) Lower electrode cost
(C) Reduced noise without processing
(D) Ability to measure joint torques
49. The center of pressure trajectory during walking is called:
(A) Gait line
(B) Pressure path
(C) Center of mass line
(D) Force line
50. Which system provides the most comprehensive biomechanical analysis when combined?
(A) MRI + X-ray
(B) EMG + Force plate + Motion capture
(C) Ultrasound + CT scan
(D) Anthropometry + DXA scan