Muscle activation during gait

Visualisation of muscle activation during gait using an anatomically-based model of the lower limbs. Concentric contraction is indicated in yellow, isometric contraction in orange and eccentric contraction in purple respectively. (Research in musculoskeletal modelling at the Auckland Bioengineering Institute)

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Fun gait analysis by Kinovea!

Kinovea is a video player for all sport enthusiasts. Slow down, study and comment the technique of your athletes or of yourself. It is 100% free and open source.

Foot analysis for runners

It is of extreme importance to have comfortable and ergonomic shoes if you are a city runner. I recently went to the Asics store in Amsterdam in order to buy a pair of running shoes. They offered me a free foot analysis before buying my runners, which I enjoyed very much. They have really good knowledge of gait analysis, especially when it has to do with city runners.

I am pointing out the major parts of the manual they gave me after my foot analysis and I add some of my knowledge in order to give you useful information on this matter:

1. Foot length

The length of your foot is measured from the end of your heel to the end of your longest toe, along an imaginary line running from the center of your heel to the end of your longest toe. For sport shoes, you should choose a size approximately 8-10 mm larger than your base foot length. This is because your feet become slightly longer in the propulsion phase o the gait cycle.

2. Ball girth (or circumference)

"Ball girth" measures around the foot, from the ball of the big toe to the ball of the little toe. Ball girth is different from foot width, which is a simple two-dimensional measurement. It is a very important measure for correct shoe fitting.

3. Heel breadth

Heel breadth is measured from the inside to the outside of the hell, at 18% of the distance of the whole foot, measuring from the back of the heel. If your heel is very narrow, you will have to place it more firmly into the heel of your shoes by tightening your laces a little more. If your heel is wide, there is no problem.

4. Instep height

Because it is related to the ball girth, instep height has a subtle effect on fitting. The place to measure the instep is roughly equal to three fingers from the base of the ankle. For example, a narrow ball girth and a high instep may not fit slim shoes.

5. Arch height

Arch height is measured by the height of the navicular bone and is directly linked to the type of arch and instep height. If your feet have low arches and your footprint shows dropped arches, you may have flat feet. Losing the basic shape of arch tends to cause more tiredness and pain.

6. Heel angle

The hell angle is the angle between the vertical line that passes through the heel and the vertical line that passes through your body center of gravity. There are two possibilities regarding the heel angle: pronation (eversion) or supination (inversion). The average is 1.5 degrees of eversion. Excessive eversion increases loading on the inner side of the foot and tiredness around the big toe. Excessive inversion increases loading on the outside of the foot decreasing stability and flexibility.

7. Toe angle

Toe angle shows the inclination of your big toe. In pathologies, it can be either valgus (outward point of the big toe) or varus (inward pointing of the big toe). Both cases have negative effects on your gait.

8. Footprints

There are two main archs in your foot, the transverse and the longitundinal arch. Depending on their height, three deformities can be distinguished:

a. Increased height of the longitundinal arch (pes cavus) - runners with high arched foot choose shoes in the under-pronator to neutral categories.

b. Loss of the longitundinal arch (flatfoot, or pes planus) - runners with flat feet should select shoes in the overpronator to severe over-pronator categories

c. Loss of the transverse arch (splayfoot, or pes tranversoplanus) - same as flatfoot runners

9. Running styles

Depending on the degree of pronation (outward movement of the foot) during running, you can be categorized in one of the three major running styles (the picture above show the right foot from behind):

a. Overpronation

 - excessive outward movement of the foot

 - more load is put on the inside part of the foot, which is transferred to the knee, hip and lower back

 - waste of energy and early fatigue

 - higher risk of injury

b. Neutral

 - balanced gait

 - efficient sock absoprtion

 - more biomechanically efficient

 - low risk of injury

c. Underpronation (or supination)

 - excessive inward movement of the foot

 - more load is put on the outside of the foot, which is transferred to the knee, hip and lower back

 - high foot arch

 - rigid foot

 - high risk of injury but very rare case

Principles of natural running

Instructional video on natural running, by Dr. Mark Cucuzzella, Director of the Natural Running Center. http://naturalrunningcenter.com.

Pelvic drop in running

I have already posted an article with some studying tips and a file I have created with all the muscles of the lower extremities with origin, insertion, action and innervation. One of the first pathologies we learn in our education is a dropping pelvis due to weak hip abductors. A pathology that can be tested with the Trendelenburg test.

In this video you can clearly see a dropping pelvis while an athlete is running. Keep in mind that the week abductors are always on the side of the leg that touches the ground at the specific moment. In this case, it appears that both sides are affected.

Iliotibial band syndrome

Tensor fasciae latae muscle

Origin: Spina iliaca anterior superior

Insertion: iliotibial band

Actions: Hip > ABD, FLEX, INT ROT

Gluteus maximus muscle

Origin: Dorsal surface of the sacrum and facies glutea of the ilium

Insertion: Upper fibers > iliotibial band, lower fibers > tuberositas glutea of the femur

Actions: Hip > EXT, EXT ROT, upper fibers > ABD, lower fibers > ADD

Iliotibial band insertion: lateral tubercle of the tibia (tuberculum of Gerdy, after French surgeon Pierre Nicolas Gerdy [1797–1856]).

Iliotibial band syndrome is a common overuse syndrome especially in long distance athletes. There are a lot of factors that can cause this syndrome, both biomechanical and training, but the exact cause is not completely understood.

When an athlete is running his foot touches the ground about 3000 times per mile. After running for 10 times he has touched the ground 30000 times. The force required to lift his body weight while running is about 3 times this weight. So, if someone weight 70 kg he will need to exert force to lift 210 kg. This means that his leg joints and muscles are loaded with extreme forces during exercise.

Biomechanics

The iliotibial band (ITB) provides the knee with stability. When the knee is in flexion over 30 degrees, the ITB is moving dorsally behind the lateral epicondyle of the femur. When the knee is extended, the ITB is moving ventrally in frond of the lateral epicondyle of the femur. This movement irritates the ITB and the bursa that lies under the insertion of it and attaching on the periosteum of the lateral epicondyle of the femur (Running News, Margaritis, 2008).

       

Research has shown that the joint capsule of the knee is folding at the point of attachment of the ITB and it is this structure that is inflamed in the ITB syndrome and not the ITB itself (Running News, Margaritis, 2008).

Causes

The ITB syndrome is an overuse syndrome which appears when the body's natural healing mechanism do not have enought time to heal the micro-damages at the point. However, there are a lot of risk factors that can increase the chances of it to appear. Here are some major causes (Running News, Margaritis, 2008):

1. Uneven leg lenght > causes variations in the function and position of the hip abductors and the pelvis bone increasing tension on the ITB

2. Genu varum > increases tension on the ITB

3. Foot overpronation > causes tibial internal rotation and hip adduction increasing tension on the ITB

4. Week hip abductors > causes increased hip adduction and internal rotation increasing tension on the ITB

5. Myofascial limitations > tight hip flexors and/or extensors and rotators increase tension on the ITB

Assessment

The pain is located at the lateral side of the knee, but it may also appear in the hip. Pain increases with running, hip and knee active flexion, hip active or passive adduction. Palpating the region can also reproduce the symptoms.

Special tests to reproduce the symptom:

Ober test > positive if the hip remains abducted.

Thomas test > positive if the knee off the bed is not flexed more than 70 degrees or hip cannot be adducted more than 15 degrees.

During assessment, the iliopsoas, the rectus femoris, the gastrocnemius and the soleus muscles should be also assessed for tightness or weakness.

How to protect yourself against the ITB syndrome

• Avoid running on hard surfaces
• Avoid running in descending surfaces
• Avoid extreme increases in your training session
• Have proper running shoes and buy new ones every 300-400 miles of training
• Stretch your legs during and after your training
• Increase knee, hip and pelvis muscle strength

Physical therapy for ITB syndrome

Acute phase - inflammation (2-5 days):

- reduce inflammation putting ice at the region for 10-15 minutes, 2 times per day

- avoid movements that reproduce the symptoms and take some rest

- add light stretching of the ITB to avoid contractures during the healing process

Later phase - proliferation (up to 6 weeks):

- facilitate fibers' normal alignemnt and prevent abnormal activation to become habitual

- increase blood flow to the region through passive activation, static stretching, gentle isometric activation with very minimum or no loading and open chain exercises, massage, and electrotherapy

- strengthen the hip abductors and external rotators, the quadriceps and the cuff muscles

- stretch the ITB and the hip adductors, extensors and internal rotators

Remodelling phase (up to 1 year):

- rebuild all locomotive properties and put the patient back to his/her daily life as functionally as possible

- use passive, active and isometric activation

- work with coordination, proprioception and functional activation

- suggested methods: ballistic stretching, PNF, dynamic stretching, weights in closed chain

- strengthen the hip abductors and external rotators, the quadriceps and the cuff muscles

- stretch the ITB and the hip adductors, extensors and internal rotators

References:

• Brody TL, Carrie MH. Therapeutic Exercise: Moving Toward, Function. 3rd ed. Philadelphia: Wolters Kluwer, Lippincott Williams & Wilkins; 2011.
• Running News. The iliotibial band syndrome. Anastasios Margaritis. c2008 [cited 2008 November 28]. URL: http://www.runningnews.gr/item.php?id=4930.
• Schuenke M, Schutle E, Schumacher U. Thieme Atlas of Anatomy: General Anatomy of the Musculoskeletal System. New York: Thieme Medical Publishers, Inc.; 2006.

Always visit your personal GP, Orthopedic MD or PT before trying anything yourself that may worsen the situation.

The importance of pelvic nutation

The relatively small and poorly defined rotational and transnational movements that occur at the sacroiliac joint in the sagittal plane are called nutation and counter-nutation.

These movements perform two major functions, based on Donald A. Neumann, Kinesiology of The Musculoskeletal System, Foundations for Rehabilitation.

1. Stress relief within the pelvic ring

2. Stability during load transfer

Regarding the first function, I have created this flowchart in order to make it understandable:

walking --> reciprocal flexion-extension pattern --> out of phase pelvic rotation --> tension in muscles and ligaments --> oppositely directed torsion --> nutation/counternutation --> stress dissipation (stress that would otherwise occur in the pelvic ring it it were a solid structure).

Regarding the second function, it is important for us to realize that nutation is the closed pack position for the SI joint. This means that the majority of joint structures are under maximal tension in this position, thus the joint is more stable. Consequently, torques that favor nutation help stabilize the SI joint. These are: gravity, stretched ligaments and muscle activation.

Gravity: the body weight line passes vetrally to the sacrum causing a forward tilt & the femural head reaction force on the acetabulutm causes an iliac bacward tilt.

Stretched ligaments: interosseous and sacrotuberous ligaments stretch the joint when movement occurs.

Muscle activation: the following muscle make the sacrum to titl forward (S) or the iliac crest to move backward (I) or just stabilize the SI joint:

erector spinae (S)
multifidus (S)
rectus abd. (I)
obliq. abd. int. & ext.
transv. abd.
hamstrings (I)
gluteus max. (I)
lat. dorsi
iliacus (S)
piriformis

Gait analysis

One of the most important and interesting things in Physical Therapy is the gait analysis and the analysis of the joints and muscles that take part in it.

I have created a small file that gives a brief overview on the phases of gait and the specific movements of each joint during them.

I think it is helpful for every student.

Here it is.

The Biomotion Lab

A beautiful tool by "The Biomotion Lab" for "playing around" with different kinds of gait depending on different criteria such as sex, body weight and mood.

The Biomotion Lab

Directed by Prof. Dr. Nikolaus Troje, the lab is located at Queen's University in Kingston, Ontario.

"Goals

We are working on several aspects of visual perception and cognition. Our major interest is focused on questions concerning the biology and psychology of social recognition. That is:

. detection of animate agents

. conspecific recognition

. gender recognition

. individual recognition

. recognition of an agent's actions

. recognition of emotions, personality traits and intentionality

. face recognition".

source: The Biomotion Lab

Types of abnormal gait

"Gait" is the pattern of how a person walks. Some types of walking problems occur without a person's voluntary control. Most, but not all, are due to some physical condition.

Some walking abnormalities have been given names:

Hemiplegic Gait

Hemiplegia is total paralysis of the arm, leg, and trunk on the same side of the body. Hemiplegia is more severe than hemiparesis, wherein one half of the body has less marked weakness. Hemiplegia and Hemiparesis may be congenital, or they might be acquired conditions resulting from an illness, an injury, or a stroke. (source: Wikipedia)

Myopathic Gait

In medicine, a myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease (myo- Greek μυο "muscle" + pathos -pathy Greek "suffering"). This meaning implies that the primary defect is within the muscle, as opposed to the nerves ("neuropathies" or "neurogenic" disorders) or elsewhere (e.g., the brain etc.). Muscle cramps, stiffness, and spasm can also be associated with myopathy.

Muscular disease can be classified as neuromuscular or musculoskeletal in nature. Some conditions, such as myositis, can be considered both neuromuscular and musculoskeletal. (source: Wikipedia)

Parkinsonian Gait

Parkinson's disease (also known as Parkinson disease, Parkinson's, idiopathic parkinsonism, primary parkinsonism, PD, hypokinetic rigid syndrome/HRS, or paralysis agitans) is a degenerative disorder of the central nervous system. The motor symptoms of Parkinson's disease result from the death of dopamine-generating cells in the substantia nigra, a region of the midbrain; the cause of this cell death is unknown. Early in the course of the disease, the most obvious symptoms are movement-related; these include shaking, rigidity, slowness of movement and difficulty with walking and gait. Later, cognitive and behavioural problems may arise, with dementia commonly occurring in the advanced stages of the disease. Other symptoms include sensory, sleep and emotional problems. PD is more common in the elderly, with most cases occurring after the age of 50. (source: Wikipedia)

Neuropathic Gait

Peripheral neuropathy is damage to nerves of the peripheral nervous system, which may be caused either by diseases of or trauma to the nerve or the side effects of systemic illness.

The four cardinal patterns of peripheral neuropathy are polyneuropathy, mononeuropathy, mononeuritis multiplex and autonomic neuropathy. The most common form is (symmetrical) peripheral polyneuropathy, which mainly affects the feet and legs. The form of neuropathy may be further broken down by cause, or the size of predominant fiber involvement, i.e., large fiber or small fiber peripheral neuropathy. Frequently the cause of a neuropathy cannot be identified and it is designated as being idiopathic. (source: Wikipedia)

Choreiform Gait

Basal ganglia disease refers to a group of physical dysfunctions that occur when the group of nuclei in the brain known as the basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function. Research indicates that increased output of the basal ganglia inhibits thalamocortical projection neurons. Proper activation or deactivation of these neurons is an integral component for proper movement. If something causes too much basal ganglia output, then the thalamocortical projection neurons become too inhibited and one cannot initiate voluntary movement. These disorders are known as hypokinetic disorders. However, a disorder leading to abnormally low output of the basal ganglia leads to relatively no inhibition of the thalamocortical projection neurons. This situation leads to an inability to suppress unwanted movements. These disorders are known as hyperkinetic disorders. (source: Wikipedia)

Diplegic Gait

Diplegia, when used singularly, refers to paralysis affecting symmetrical parts of the body. This should not be confused with hemiplegia which refers to spasticity restricted to one side of the body, or quadriplegia which requires the involvement of all four limbs but not necessarily symmetrical. Diplegia is the most common cause of crippling in children, specifically in children with Cerebral Palsy. Other causes may be due to injury of the spinal cord. There is no set course of progression for people with diplegia. Symptoms may get worse but the neurological part does not change. The primary parts of the brain that are affected by diplegia are the ventricles, fluid filled sacs in the brain, and the wiring from the center of the brain to the cerebral cortex. There is also usually some degeneration of the cerebral neurons, as well as problems in the upper motor neuron system. The term diplegia can refer to any bodily area, such as the face, arms, or legs. (source: Wikipedia)

Ataxic Gait

Ataxia (from Greek α- [a negative prefix] + -τάξις [order] = "lack of order"), is a neurological sign consisting of lack of voluntary coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum. Several possible causes exist for these patterns of neurological dysfunction. The term "dystaxia" is a rarely used synonym. (source: Wikipedia)