anatomy and biomechanics of soleus muscle

1. ANATOMY AND
BIOMECHANICS
OF
SOLEUS MUSCLE
SUBMITTED TO:- MONIKA MAM
SUBMITTED BY:- JASMEEN KAUR
B.P.T. 2nd YEAR
ROLL NO. :- 38

2. INTRODUCTION:
SOLEUS Muscle Is a Sole-Shaped Multi pennate Muscle.
It Lies Deep To The Gastrocnemius Muscle.
It Is Located In Posterior Compartment Of Leg.
It Is a Powerful Limb Muscle Which Along With The
Gastrocnemius And Plantaris Forms Calf Muscle.
It Runs From Back Of The Knee To Ankle.
The Soleus Muscle Is Also Called The Peripheral Heart As
When It Contracts The Blood In Sinuses is Pumped Upwards
And When It Relaxes, It Sucks The Blood From Superficial Veins
Through The Perforators.

3. ANATOMY:
a) The Fibula: Back of head, and upper one-fourth of
posterior surface of the shaft.

4. b) Tibia: Soleal line and middle one-third of the medial
border of the shaft.
c)The tendinous soleal arch
that stretches between the
tibia and the fibula.
INSERTION:
The Tendon of Gastrocnemius muscle
fuses with the Tendon of Soleus
Muscle to form the Tendo
Calcaneus, which is inserted into
the middle one-third of the
posterior surface of the
calcaneum.

5. NERVE SUPPLY:
Tibial Nerve (Muscular Branch)
ACTION:
• The Soleus and Gastrocnemius are Strong Plantar Flexors of
The Foot at The Ankle Joint, Which is Very Important In
Walking And Running.
• To Act As Muscle Pump: Along with other calf muscles it
is known as PERIPHERAL HEART as in upright posture it
enhance pumping the venous blood back into heart from
periphery.
• In Walking, The Soleus Overcomes The Inertia of The Body
Weight, Just Like The Bottom Gear of The Car.
• Soleus Is Chiefly a Postural Muscle To Steady The Leg on
Foot.

6. SYNERGISTS:
Gastrocnemius, Plantaris, Tibialis Posterior, Peroneus Longus
and Brevis, FHL and FDL.
ANTAGONISTS:
Tibialis Anterior.
BLOOD SUPPLY:
• Blood Supply of Soleus Muscle is From Peroneal Artery
Proximally and The Posterior Tibial Artery Distally.
• Muscle Has a Mixed Blood Supply.
• Vascular Supply of the Soleus Muscle is From the Posterior
Tibial, Popliteal & Peroneal Vascular Pedicles to the
Proximal Muscle , Peroneal Pedicles to Distal Lateral Belly,
and Segmental Posterior Tibial Pedicles to Distal Medial
Belly.

7. CLINICAL ANATOMY OF SOLEUS
MUSCLE:
STRAIN/RUPTURE :
Full or partial rupture of the soleus muscle usually occurs when the
calf muscle becomes stretched while it is contracting (eccentric
contraction). Partial ruptures represent the majority of the
ruptures. The ruptures occur in many instances at the point of
attachment of the soleus muscle to the tendo calcaneus, which will
often trigger an inflammation of the tendo calcaneus as a result of
soleus rupture.
Symptoms: Pain when activating the calf muscle (running and
jumping), when applying pressure on the tendo calcaneus
approximately 4 cm above the anchor point on the heel bone or
higher up in the calf muscle, and when stretching the tendon.
Walking on tip-toe will aggravate the pain. In all cases when there is
a sense of a “crack”, or sudden shooting pains in the tendon,
medical attention should be sought as soon as possible. Ultrasound
scanning or MRI examination is used to advantage when making
the diagnosis, as even full ruptures can easily be overlooked by
normal clinical examination.

8. SOLEUS SYNDROME:
Another cause of medial pain (posteromedial aspect of ankle)
just above the medial malleolus is the soleus syndrome. It
occurs because of soleus muscle from its normal origin site
and is similar to exertional compartment syndrome and
commonly seen in dancers and athletes. Respond well to
conservative treatment and if not then rarely fasciotomy of
the soleus insertion may be required.

9. BIOMECHANICS
Muscle Structure:
The soleus muscle contains up to 80% type 1 fibers.
These muscles are often called stability or postural
muscles. The relatively small, slow motor units of the
soleus muscles are almost continually active during erect
standing in order to make the small adjustments in
muscle tension that are required to maintain body
balance and counteract the effects of gravity.
Contribution In Ankle Movement:
The Soleus and the Gastrocnemius together eccentrically
control dorsiflexion of the ankle while also supinating the
subtalar joint after the foot is loaded in stance. These muscles
provide supination torque that contributes to making the foot a
rigid lever for push-off and continue to provide plantarflexion
torque throughout heel raise and plantarflexion of the ankle as
the ground reaction force moves to metatarsal heads and toes.

10. Shortening Of The Soleus Muscle:
Because the soleus and gastrocnemius muscles pass behind the
ankle joint, a limitation in the length of the muscles results in
limited dorsiflexion ROM.
Contribution of Soleus in Knee Extension:
The Soleus and gluteus maximus muscle do not cross the knee
joint. However, they have function at
knee during weight-bearing activities. The
soleus muscle attaches proximally to the
proximal posterior aspect of the tibia and
fibula & attaches distally to calcaneal tendon.
With the foot fixed on the ground during
weight-bearing, a soleus muscle contraction
can assist with knee extension by pulling the
tibia posteriorly. The posterior pull of the
soleus on the weight-bearing leg can also assist the hamstrings in
restraining excessive anterior displacement of the tibia.

11. Role of Soleus in Standing Posture:
In sagittal plane,
The anterior position of the LoG in relation to the ankle
joint axis creates an external dorsiflexion moment that must
be opposed by an external plantarflexion moment to prevent
forward motion of tibia. The soleus
muscles contract and exert a posterior
pull on the tibia and in this way is able
to oppose the dorsiflexion moment.
Activity of soleus muscle may augment
the gravitational extension moment at
the knee through its posterior pull on
the tibia as it acts at the ankle joint.

12. In Flexed Knee Postural Deviation, increased soleus muscle
activity may be required to create internal plantarflexion
moment to counteract the increased external dorsiflexion
moment at the ankle.

13. Sagittal Plane Moment:
The sagittal plane moment profiles for the ankle is shown with the
joint angle profiles and muscle work in figure below.
Fig.[ Joint angles and net joint moments in sagittal plane, and
EMG profiles of major contributors to joint moments of ankle
during adult gait.]

14. Muscle Activity of Soleus in Gait Cycle:
A smooth increasing contraction of the ankle plantar
flexors (soleus, medial and lateral gastrocnemius
muscles and other contributors) that continues until mid-
push-off and then declines and ceases at about 60% of the
cycle. The largest contribution to the work of walking comes
from the ankle plantar flexors ( largely soleus, medial and
lateral gastrocnemius muscles). These muscles work
eccentrically(lengthening) from early stance until about 40%
of the gait cycle, when they are
controlling the forward
movement of the tibia over the
talus as the upper body passes
over the foot. At about 40% of
the gait cycle, they produce a
burst of concentric activity (A2-S) ending at toe-off.

15. Gait Characteristics From
1) INITIAL CONTACT to MID STANCE :
Joint – Ankle joint.
Motion – Plantar flexes from 0° to -5° , then dorsiflexes to +5°
Ground reaction force – Posterior to anterior
Internal moment – Dorsiflexor , then plantarflexor
Power – Absorption (dorsiflexors) , Generation (plantarflexors)
Major muscle activity – Soleus, Tibialis Anterior, Gastrocnemius.
2) MIDSTANCE to TOE-OFF :
Joint – From +5° dorsiflexion, dorsiflexes a few more degrees, then
rapidly plantarflexes to -25°
Ground reaction force – Anterior
Moment – Plantarflexor
Power – Very small absorption (plantarflexors), large generation
(dorsiflexors)
Major muscle activity – Soleus, gastrocnemius.

16. Sagittal Plane Analysis of Stair Ascent
1. Stance Phase
• Weight Acceptance (0% -14% of Stance phase)
through Pull-Up (14% -32% of stance phase) :
Joint – Ankle
Motion – Dorsiflexion: 20°- 25° of dorsiflexion
Plantarflexion: 25°- 15° of plantarflexion
Muscle – Tibialis anterior, Soleus and Gastrocnemius
Contraction – Concentric.
• Pull-Up (end of pull-up) through Forward
Continuance (32%- 64% of the stance phase):
Joint – Ankle
Motion – Plantarflexion: 15° of dorsiflexion to 15°- 10° of
plantarflexion
Muscle – Soleus, Gastrocnemius, Tibialis Anterior
Contraction – Concentric, Eccentric

17. Average Peak ROM at the Ankle:
Plantarflexion:
Running – 20° - 30°
walking – 20°