Muscle Testing (Biomechanics) Flashcards
Why is muscle testing important?
Assesses whether muscles are acting as they are supposed to. Weak muscles can affect gait & stance & can be strengthened.
What is the action of Tibialis Posterior?
Plantar flexion & inversion of foot
If flexor hallucis longus & flexor digitorum longus are substituting what will occur?
Toes strongly flex
How is Tibialis Posterior tested?
- Pt supine/ sitting
- Fixate above ankle
- Dorsiflex ankle & evert foot
Tibialis posterior weakness is seen clinically as?
If weak single limb raise difficult/ impossible & gross pronation
What is the action of Tibialis Anterior?
Dorsiflexion & Inversion of foot
How is Tibialis Anterior Tested?
- Pt supine/ sitting
- Fixate above ankle
- Plantar flex ankle & evert foot
Tibialis anterior weakness results in?
Gross pronation & dropfoot
What is the action of soleus?
Plantar flexion of foot (without inversion or eversion)
- Inversion/ eversion indicates tibialis posterior? toe flexors or peroneal substitution
How is soleus tested?
- Pt prone (lying face down) with knee flexed
- Fixate leg proximal to ankle
- Dorsiflex foot using calcaneus or plantar surface of foot
Soleus weakness is seen clinically as?
- Cavus position of foot &
- Inability to rise on toes
- Anterior displacement of body, possibly with knee flexion
What is the action of Gastrocnemius?
Plantar flexion of foot
How is gastrocnemius tested?
- Pt prone (lying face down) with knee extended
- Pressure against plantar surface of foot (If Pt is strong)
- Pressure against calcaneus only (If Pt is weaker)
Gastrocnemius weakness is seen clinically as?
The inability to rise on toes &
Hyperextension of knees
What is the action of Peroneus Longus & Brevis?
Eversion & Plantar flexion of foot
Peronus Longus & Brevis weakness is seen clinically as?
Varus position of foot
Decreased lateral stability
Rising on toes
What is the action of Extensor Hallucis Longus &
Extensor Digitorum Brevis (medial slip)?
Extensor Hallucis Longus dorsiflexes the hallux @ the MPJ & assists ankle dorsi flexion
How is Extensor Hallucis Longus & Extensor Digitorum Brevis tested?
- Pt supine or sitting
- Fixate foot behind ankle in plantar position
- Pressure against dorsal surface of hallux
Extensor Hallucis Longus & Extensor Digitorum Brevis weakness is seen clinically as?
Decreased hallux & ankle joint extension,
allowing flexed position of toe
What is the action of extensor digitorum longus & brevis?
Dorsi flexion of all joints of lesser digits &
Aids dorsi flexion at ankle joint
How is extensor digitorum longus & brevis tested?
- Pt supine/ sitting
- Fixate behind ankle with foot plantar flexed
- Apply pressure against dorsal surface of lesser toes
Weakness of extensor digitorum longus & brevis results in?
Foot drop & forefoot varus
What is the action of Flexor Hallucis Brevis?
Plantar flexion of hallux at MPJ
How is Flexor Hallucis Brevis tested?
- Pt supine/ sitting
- Fixate foot & ankle
- MPJ in neutral position
- Apply pressure against plantar surface of proximal phalanx of hallux
Weakness of Flexor Hallucis Brevis results in?
Hammering of hallux &
Decreased stability of the longitudinal arch
What is the action of Flexor Hallucis Longus?
Plantar flexion of IPJ of hallux
Aids plantar flexion of MPJ, ankle joint & inversion of foot
How is Flexor Hallucis Longus tested?
- Pt supine/ sitting
- Hold foot, ankle & 1st MPJ in neutral
- Apply pressure against the plantar surface of the distal phalanx of hallux
Weakness of Flexor Hallucis Longus is seen clinically as?
Decreased inversion strength of foot
Plantar flexion of ankle with hallux hyperextended/ hammering
What is the action of the Hamstrings?
Knee flexion & hip extension
How are the hamstrings tested?
- Pt prone
- Fixate thigh firmly on table
- Pressure against calf
(medially orientated leg for semi-membranosus & semi-tendinosus)
(laterally orientated leg for biceps femoris at 50-70 degrees)
Weakness of hamstrings is seen clinically as?
Hyperextension of knee
If bilateral -> anterior tilt of pelvis & lumbar lordosis
Loss of medial or lateral strength = knock knees or bow legs
What is the action of Quadriceps Femoris?
Knee extension
How is Quadriceps Femoris tested?
- Pt sitting with knees over edge of bed/ plinth
- Apply pressure against dorsum of leg above the ankle
Weakness of Quadriceps Femoris results in?
Difficult climbing stairs or inclines
Difficulty rising from a chair
Hyperextension of knees
What is the action of Hip Flexors?
Flexion of the hip
Hip Flexor weakness results in?
Difficulty climbing stairs or inclines
Difficulty rising from supine (lying down) position
Difficulty rising from chair
What is the action of Flexor Digitorum Longus/ Quadratus Plantae?
Plantar flexion of the lesser toe joints
Assists in plantar flexion and inversion of foot
How is Flexor Digitorum Longus/ Quadratus Plantae tested?
- Pt supine/ sitting
- Fixate foot & ankle in neutral position
- Stabilise metatarsals
- Apply pressure against the plantar surface of the distal phalanx of lesser toes
Weakness of Flexor Digitorum Longus/ Quadratus Plantae results in?
Hyperextension of distal phalanges 2-5
Decreased ability to invert foot
Plantar flexion at ankle joint
Increased pronation (in stance)
What is the action of Flexor Digitorum Brevis?
Plantar flexion of the proximal IPJ &
Flexion of MPJs of digits 2-5
How is Flexor Digitorum Brevis tested?
- Pt supine/ sitting
- Fixate foot & ankle in neutral (& proximal phalanges)
- Apply pressure against the plantar surface of middle phalanges 2-5
Weakness of Flexor Digitorum Brevis results in?
Decreased support of longitudinal & transverse arches
