Return to Help Centre

Sensor Positioning

Muscle function neural drive & effort
Abductor Pollicis Brevis
Adductors
Biceps
Brachioradialis
Calf Muscle Analysis
Core Analysis
Deltoids (Front)
Deltoids (Lateral)
Deltoids (Rear)
Deltoids (Together)
Erector Spinae (Lumbar)
Erector Spinae (Thoracic)
Extensor Digitorum
External Oblique
Flexor Carpi Radialis
Flexor Carpi Ulnaris
Forearm Flexors (Together)
Frontalis
Gastrocnemius
Gluteus Maximus
Gluteus Medius
Hamstrings
Hand
Hip Complex Analysis Examples
Infraspinatus
Latissimus Dorsi
Lower Back-Lumbar Extensors-Erector Spinae
Lower Trapezius
Masseter
Middle Trapezius
Multifidus
Neck Extensors And Rotators
Palmaris Brevis
Pectoralis Major
Peroneus Longus
Quadriceps (Muscle Outputs)
Quadriceps (Rectus Femoris)
Quadriceps (Tensor Fascia Latae)
Quadriceps (Together)
Quadriceps (Vastus Lateralis)
Quadriceps (Vastus Medialis)
Rectus Abdominus
Serratus Anterior
Shoulder (Deltoids & Pectoralis)
Shoulder (Deltoids & Upper Trapezius)
Shoulder (Lats & Lower Traps)
Shoulder (Lower Shoulder Analysis)
Shoulder (Posterior 4 Sensor Analysis)
Soleus
Sternocleidomastoids
Tibialis Anterior
Transverses Abdominus (TvA) External
Trapezius Muscle Placement Sites
Triceps
TvA Obliques Muscle Outputs
Upper Trapezius

Muscle function neural drive & effort

What is electromyography?

EMG (electromyography) is a technique used to measure electrical signals (action potentials) in muscle fibres. The signals are the result of electrical excitation of the muscle by the motor control systems of the nervous system transmitted to muscles by motor nerves. Motor action potentials trigger muscle contraction by a process known as excitation-contraction coupling.

What does EMG measure?

The EMG signal is a direct measure of the neural drive to the muscle and an indirect estimate of the contraction force generated by the neural drive.

Here are examples of four muscle groups showing the correlation between neural drive and muscle excitation. As the weight being moved by the muscles increases so does the contraction force generated by the neural drive.

Pec Major neural drive load test
Biceps neural drive load test
Triceps neural drive load test
Quadriceps neural drive load test

Abductor Pollicis Brevis

Consider testing this muscle for:

  • Abduction of the carpometacarpal joint of the first digit
Male maximal voluntary contractions
Female maximal voulntary contractions

Adductors

Consider testing these muscles for:

  • Hip adduction, extension, weak flexion, internal rotation, and stabilization of the pelvis.
Male maximal voluntary contractions
Female maximal voulntary contractions

Biceps

Consider testing these muscles for:

  • Flexion of the elbow joint; supination, adduction, and internal rotation of the humerus.
Male maximal voluntary contractions
Female maximal voulntary contractions

Brachioradialis

Consider testing this muscle for:

  • Flexion of the elbow, supination and pronation of the forearm.
Female maximal voulntary contractions
Male maximal voluntary contractions
Male maximal voluntary contractions

Calf muscles analysis, Gastrocnemius and Soleus

Consider testing these muscles for:

  • Gastrocnemius: plantar flexion of the talocrural joint; flexion of the knee joint
  • Soleus: plantar flexion of the foot
Female Calf muscle activity walking
Female Calf muscle activity jogging on the spot
Female Calf muscle activity pushing a treadmill with resistance
Male Calf muscle activity walking
Male Calf muscle activity jogging on the spot
Male Calf muscle activity pushing a treadmill with resistance

Examples of sensor placement for core analysis using three and four sensors

External and internal Obliques, Transversus abdominus

Consider testing these muscles for:

  • External Oblique: Lateral flexion of the trunk ipsilaterally; rotation of the trunk contralaterally; compression of the abdomen to stabilize the pelvis.
  • Internal Oblique: Flexion and lateral flexion of the trunk ipsilaterally; rotation of the trunk contralaterally.
  • Transversus abdominus: abdominal hollowing, rotation, flexion, and lateral flexion of the trunk

Front Deltoid

Consider testing this muscle for:

  • Abduction of the arm, flexion and internal rotation.
Male shoulder muscle activity during shoulder flexion
Male Lateral and rear deltoids maximal voluntary contractions
Male shoulder muscle activity during shoulder adduction

Lateral Deltoid

Consider testing this muscle for:

  • Abduction of the arm.
Female isometric contractions of lateral and rear deltoids
Male isometric contractions of lateral and rear deltoid

Rear Deltoid

Consider testing this muscle for:

  • External rotation and extension of the arm.
Female deltoids maximal voluntary contractions
Male shoulder muscle activity during shoulder extension
Male Rear Deltoids muscle activity during cable row with 80 kg
Male shoulder muscle activity during shoulder extension

Deltoids

Consider testing these muscles for:

  • Abduction of the arm, flexion and internal rotation via the anterior fibres, external rotation and extension via the posterior fibres.
Deltoid Female muscle outputs during isometric voluntary contractions
Male Deltoid muscle outputs during isometric voluntary contractions

Erector Spinae (Lumbar)

Consider testing the Erector Spinae muscles for

  • Lumbar extension and lateral flexion of the trunk
  • Lumbar flexion relaxation phenomenon test.
Female maximal voluntary contractions
Male maximal voluntary contractions

Erector Spinae (Thoracic)

Consider testing the Erector spinae thoracic for:

  • Lumbar extension and lateral flexion of the trunk.
Female maximal voluntary contractions
Male maximal voluntary contractions

Extensor Digitorum

Consider testing this muscle for:

  • Extension of the wrist; extension of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 2nd-5th fingers; abduction of the fingers.
Female muscle activity from isometric hold
Female maximal voluntary contractions
Male maximal voluntary contractions

External Oblique

Consider testing this muscle for:

  • Lateral flexion of the trunk ipsilaterally; rotation of the trunk contralaterally; compression of the abdomen and stabilization of the pelvis.
Female Transverses abdominus and Obliques muscle activity during abdominal bracing
Female Transverses abdominus and Obliques muscle activity during press up hold position
Male Transverses abdominus and Obliques muscle activity during prone hold exercise

Flexor Carpi Radialis

Consider testing this muscle for:

  • Flexion of the wrist and abduction of the hand
Female muscle activity from isometric squeeze
Female maximal voluntary contractions
Male maximal voluntary contractions

Flexor Carpi Ulnaris

Consider testing this muscle for

  • Flexion of the wrist and abduction of the hand
Female muscle activity from isometric squeeze
Female maximal voluntary contractions
Male maximal voluntary contractions

Forearm Flexors (Together)

Flexor carpi radialis, Flexor carpi ulnaris, Brachioradialis

Consider testing these muscles for

  • Flexion of the wrist and abduction of the hand.
  • Flexion of the elbow; supination and pronation of the forearm.

Frontalis

Consider testing this muscle for:

  • Elevation of the eyebrows and wrinkles to the skin of the forehead.
Female Frontalis maximal voluntary contractions
Male Frontalis maximal voluntary contractions

Gastrocnemius

Consider testing this muscle for:

  • Plantar flexion of the talocrural joint and flexion of the knee joint.
Male Gastrocnemius and Soleus maximal voluntary contractions
Female Gastrocnemius and Soleus maximal voluntary contractions

Gluteus Maximus

Consider testing this muscle for:

  • Extension of the femur from the flexed position in the hip joint; lateral stabilisation of the hip and knee joints; external rotation of the femur.
Male Glute max maximal voluntary contractions
Female Gluteal muscles maximal voluntary contractions
Female Gluteal muscles activity from flexed hip extensions with 20 kg
Male Glute max activity squatting 60 kg
Female maximal voluntary contractions
Female 90 kg squat muscle outputs
Female 90 kg hip thrusts muscle outputs
Female maximal voluntary contractions
Male maximal voluntary contractions
Female supported hip extension muscle outputs
Female Gluteal activity from hip thrusts with 30 kg dummbbell
Male Glute max muscle activity walking

Gluteus Medius

Consider testing this muscle for:

  • Abduction of the hip and stabilisation of the pelvis; Anterior part: flexion and internal rotation; Posterior part: extension and external rotation.
Female lying leg abduction
Female standing leg abduction
Female fire hydrant
Female walking muscle activity
Female treadmill push muscle activity
Male maximal voluntary contractions

Hamstrings

Biceps femoris, Semimembranosus, Semitendinosus.

Consider testing these muscles for:

  • Biceps femoris: flexion and external rotation of the knee joint.
  • Semimembranosus: extension of the hip joint; stabilisation of the pelvis; flexion and internal rotation of the knee joint.
  • Semitendinosus: extension of the hip joint; stabilisation of the pelvis; flexion and internal rotation of the knee joint.
Female Hamstrings maximal voluntary contractions
Female muscle activity during hamstring sliders exercise
Female muscle activity during lying leg curls in hip extension with 10 kg
Female muscle activity during Nordic hamstring exercise
Female muscle activity during stiff leg deadlifts with 30 kg
Male hamstrings activity during Nordic hamstrings exercise
Male hamstrings maximal voluntary contractions
Male hamstrings muscle activity during lying leg curls exercise in hip exetnsion
Male hamstrings muscle activity during flexed hip extension exercise
Male hamstrings muscle activity walking

Hand

Abductor pollicis brevis, Palmaris brevis

Consider testing these muscles for:

  • Abductor pollicis brevis: abduction of the carpometacarpal joint of the first digit.
  • Palmaris brevis: Tightening of the palmar aponeurosis and pulls the skin of the ulnar side of the hand to the centre of the palm.
Male maximal voluntary contractions
Female maximal voulntary contractions

Hip Complex Analysis Examples

Vastus Lateralis, Tensor Fasciae Latae, Gluteus Medius and Multifidus

Consider testing these muscles for:

  • Vastus lateralis: extension of the knee joint
  • Tensor fasciae latae: tenses the fascia lata; abduction, flexion and internal rotation at the hip joint
  • Gluteus medius: abduction of the hip and stabilisation of the pelvis; Anterior part: flexion and internal rotation; Posterior part: extension and internal rotation
  • Multifidus: extension, ipsilateral lateral flexion and contralateral rotation of the spine
Male hip complex muscle activity during hip flexion and extension
Male hip complex muscle activity during single leg stance
Male hip complex muscle activty during standing hip abduction left leg
Hip complex muscle activity during walking gait
Hip complex innactive Glute med during hip extension test
Female hip complex standing maximal voluntary contractions
Female hip complex standing hip flexion muscle activity
Hip complex muscle activity during walking gait
Female hip complex walking muscle activity
Female hip complex bike erg muscle activity

Infraspinatus

Consider testing this muscle for:

  • External rotation of the arm
Female maximal voluntary contractions
Female hip complex walking muscle activity

Latissimus Dorsi

Consider testing this muscle for:

  • Extension, adduction, and internal rotation of the arm; also aids in respiration
Male Latissimus dorsi maximal voluntary contractions
Male Latissimus dorsi maximal voluntary contractions example 2
Female maximal voluntary contractions upper and lower lats
Male Latissimus dorsi muscle activity during cable row with 80 kg

Lower Back-Lumbar Extensors-Erector Spinae

Consider testing these muscles for

  • Lumbar/thoracic extensors: lumbar extension and lateral flexion of the trunk
  • lumbar flexion relaxation phenomenon test.
  • Multifidus: extension, ipsilateral lateral flexion, and contralateral rotation of the spine.
Female Superman maximal voluntary contractions
Female flexion relaxation phenomonen test
Female Superman muscle outputs
Female 90 kg squat muscle outputs
Male Lower back activity performing squats with 60 kg
Male Lower back activity walking
Male Superman exercise to measure lumbar extensors maximal voluntary contractions

Lower Trapezius

Consider testing this muscle for:

  • Depression of the shoulders and aiding the upper Trapezius fibres in upwardly rotating the scapula.
Male Lower Trapezius during Prone Cobra exercise
Female muscle output during Superman exercise
Male Muscle activity during shoulder flexion
Male Lower Trapezius maximal voluntary contractions

Masseter

Consider this muscle when testing

  • Elevation, adduction, and protrusion of the mandible.
Female Masseter maximal voluntary contractions
Male Masseter maximal voluntary contractions

Middle Trapezius

Consider this muscle when testing for:

  • Retraction, superior rotation, and depression of the scapula.
Female maximal voluntary contractions
Male maximal voluntary contractions
Female muscle activity during shoulder flexion
Female muscle activity during Superman exercis

Multifidus

Consider testing this muscle for:

  • Extension, ipsilateral lateral flexion, and contralateral rotation of the spine.
Female Multifidus muscle activity during four point Bird dog test
Female Multifidus muscle activity during negitive flexion relaxation phenomonen test
Female Multifidus walking muscle activity
Male Multifidus hyperactivity during standing posture
Male Multifidus hyperactivity during standing posture
Female Superman exercise to measure multifidus maximal voluntary contractions

Neck Extensors And Rotators

Consider testing these muscles for

  • Extension and lateral flexion of the head and neck; ipsilateral rotation of the head.
Female Multifidus muscle activity during negitive flexion relaxation phenomonen test
Male cevical neck extensors - rotators  maximal voluntary contractions.

Palmaris Brevis

Consider testing this muscle for:

  • Tightening of the palmar aponeurosis and pulls the skin of the ulnar side of the hand to the centre of the palm.
Male maximal voluntary contractions
Male maximal voluntary contractions

Pectoralis Major

Consider testing this muscle for:

  • Adduction, internal rotation, and flexion of the arm; also assist in respiration when the shoulder is fixed.
Female Pec major maximal volunatry contractions
Male Pec major maximal voluntary contractions
Male Pec major muscle activity from dummbbell chest press with 30 kg dummbbells

Peroneus Longus

Consider testing this muscle for:

  • Plantar flexion of the talocrural joint and eversion of the subtalar joint.
Female examples of maximal voluntary contractions
Female example of muscle outputs walking
Male example of maximal voluntary contractions
Male example of muscle outputs walking

Quadriceps (Muscle Outputs)

Vastus medialis, Rectus femoris, Vastus lateralis, Tensor fasciae latae

Consider testing these muscles for

  • Vastus Medialis: extension of the knee joint.
  • Rectus Femoris: Flexion of the hip joint and extension of the knee joint.
  • Vastus Lateralis: Extension of the knee joint.
  • Tensor fasciae latae: tenses the fascia lata; abduction, flexion and internal rotation at the hip.
Female Quadriceps maximal voluntary contractions
Male Quadriceps maximal voluntary contractions
Quadriceps muscle activity of subject walking
Male Quadriceps muscle outputs using bike erg
Female Quadriceps muscle activity using Bike erg
Male Quadriceps muscle activity during Leg extension with 45 kg
Male Quadriceps muscle activity during squats with 90 kg
Male Quadriceps muscle activity during Bulgarian split squats with 20 kg dummbbells
Subject with right knee OA showing variance in muscle outputs

Quadriceps (Rectus Femoris)

Consider testing this muscle for

  • Flexion of the hip joint and extension of the knee joint.

Quadriceps (Tensor Fascia Latae)

Consider testing this muscle for:

  • Tenses the fascia lata; abduction, flexion and internal rotation at the hip

Quadriceps (Together)

Vastus medialis, Rectus femoris, Vastus lateralis, Tensor fasciae latae

Consider testing these muscles for:

  • Vastus Medialis: extension of the knee joint
  • Rectus femoris: Flexion of the hip joint and extension of the knee joint
  • Vastus Lateralis: Extension of the knee joint
  • Tensor Fasciae Latae: tenses the fascia lata; abduction, flexion, and internal rotation at the hip

Quadriceps (Vastus Lateralis)

Consider testing this muscle for

  • Extension of the knee joint

Quadriceps (Vastus Medialis)

Consider testing this muscle for:

  • Extension of the knee joint.

Rectus Abdominus

Consider testing this muscle for:

  • Compression of the abdomen; flexion of the trunk; stabilisation of the pelvis.
Female maximal voluntary contractions
Female muscle activity during prone hold
Male maximal voluntary contractions

Serratus Anterior

Consider testing this muscle for:

  • Superior external rotation of the scapula; draws the scapula internally and forwards; lowers the arm from a raised position; elevation of the ribs
Male Serratus anterior maximal voluntary contractions example 2
Male Serratus anterior activity during Curl up reach exercise
Male Serratus anterior maximal voluntary contractions

Shoulder (Deltoids & Pectoralis)

Example of four sensor shoulder analysis.

  • Anterior, lateral, and rear Deltoid muscles, and Pectoralis major.

Shoulder (Deltoids & Upper Trapezius)

Example of four sensor shoulder analysis.

  • Anterior, Lateral and Rear Deltoid Muscles, and Upper Trapezius.

Shoulder (Lats & Lower Traps)

Example of two sensor shoulder analysis.

  • Lower Trapezius and Latissimus Dorsi

Shoulder (Lower Shoulder Analysis)

Example of four sensor shoulder analysis.

  • Middle and Lower Trapezius, Infraspinatus and Latissimus Dorsi.

Shoulder (Posterior 4 Sensor Analysis)

Example of four sensor shoulder analysis.

  • Upper, Middle, and Lower Trapezius, and Infraspinatus.

Soleus

Consider testing this muscle for:

  • Plantar flexion of the talocrural joint and plantar flexion of the foot.
Male Gastrocnemius and Soleus maximal voluntary contractions
Female Gastrocnemius and Soleus maximal voluntary contractions

Sternocleidomastoids

Consider testing this muscle for:

  • Inclines the head ipsilaterally and rotates it contralaterally.
Femaile Sternocleidomastoid maximal voluntary contractions right side
Female Sternocleidomastoid maximal voluntary contractions left
Male Sternocleidomastoid maximal voluntary contractions right
Male Sternocleidomastoid maximal voluntary contractions left

Tibialis Anterior

Consider testing this muscle for:

  • Dorsal flexion of the talocrural joint and inversion of the subtalar joint.
Male Tibialis anterior maximal voluntary contractions
Female Tibialis anterior maximal voluntary contractions

Transverses Abdominus (TvA) External

Consider testing this muscle for:

  • Rotation, flexion, and lateral flexion of the trunk: abdominal hollowing.
Male maximal voluntary contractions via abdominal hollowing
Female maximal voluntary contractions via abdominal hollowing

Trapezius Muscle Placement Sites

Examples of two and three sensor Trapezius analysis.

Triceps

Consider testing these muscles for:

  • Extension of the elbow joint to extend the forearm.
Female maximal voluntary contractions.
Male Triceps maximal voluntary contractions
Male Triceps activity during straight bar Triceps pushdowns
Male Triceps activity during Triceps kickback exercise with 10 kg

TvA Obliques Muscle Outputs

External and Internal Obliques, Transversus Abdominus.

Consider testing these muscles for:

  • External Oblique: Lateral flexion of the trunk ipsilaterally; rotation of the trunk contralaterally; compression of the abdomen to stabilize the pelvis.
  • Internal Oblique: Flexion and lateral flexion of the trunk ipsilaterally; rotation of the truck contralaterally.
  • Transversus abdominus: abdominal hollowing, rotation, flexion, and lateral flexion of the trunk.
Male Tranverse abdominus hyperactivey during standing posture
Male Transverses abdominus hyperactivity during walking gait
Male Transverses abdominus and Obliques muscle activity walking
Male Transverses abdominus and Obliques muscle activity during press up hold position
Female Transverses abdominus and Obliques muscle activity walking
Female Transverses abdominus and Obliques muscle activity during prone hold
Female Transverses abdominus and Obliques muscle activity walking with abdomen distended

Upper Trapezius

Consider testing this muscle for:

  • Elevation of the scapula, ipsilateral side flexion of the neck, head rotation, adduction of the arm.
  • Hyperactivity (Cinderella syndrome).
Female Upper Trapezius maximal voluntary contractions
Male Upper Trapezius maximal voluntary contractions
Female Upper Trapezius activity walking - with no hyperactivity
Female Maximal voluntary contractions
Male maximal voluntary contractions
Female muscle activity during Superman exercise