Flat Feet: short overview by sports physiotherapist.

 

Flat feet
(Ref: https://www.fixflatfeet.com/)

Flat foot is a common postural deformity that we have seen flat feet ordinary. We have thought flatfeet would always cause foot problems. This topic would be a bit deeper review of flat feet such as arch development, type of flat feet, and musculoskeletal disorders.

Prevalence of flat feet in children is inversely proportional with age. Higher prevalence (21% to 57%) has been reported among children of 2 to 6 years that the prevalence declines in primary school children (13.4% to 27.6%). While prevalence of flat feet in adults has been reported to be between 13.6% to 26.62%. 

Type of flat feet

Flatfoot is characterized clinically by hindfoot valgus or eversion, forefoot supination in relation to the hindfoot, and a diminished or nonexistent medial longitudinal arch. Flat - feet that we have seen in normal life, however, the conditions can be divided into two types including rigid and flexible. 

A rigid flat foot is characterized by a stiff, collapsed arch in both weight-bearing and non-weight-bearing positions. The differential diagnosis of Pediatric flat foot deformity consists of Rigid flatfoot with tarsal coalition, Rigid flatfoot without tarsal coalition, so - called peroneal spastic flatfoot, Inflammatory arthritic flatfoot, Neoplastic flatfoot.

Rigid flat feet that be flat both of non - weight and during weight bearing
(Ref: https://samantha153.wordpress.com/category/flat-feet/) 

Whereas a flexible flat foot is characterized by a normal - appearing arch when the foot is not bearing weight but by a flattened arch when weight - bearing. Flexible flat feet are the most common type of flat foot. Harris and Beath have classified the flexible flat feet account for approximately 2/3 of all flat - foot occurrences. 

A flexible flat foot results in hyperpronation, plantar flexion, adduction of the talus, and calcaneal eversion. If a flexible flat foot is neglected, it can worsen to become a rigid flat foot, resulting in a loss of flexibility, hindfoot eversion, and joint deformity with pain. From a biomechanical point of view, a flexible flat foot can cause some musculoskeletal problems because they require more energy consumption when performing movements such as walking, and running. The differential diagnosis of Pediatric flat foot deformity consists of Flexible flatfoot including Physiologic flexible flatfoot, Physiologic flexible flatfoot with short tendo - Achilles, Flexible flatfoot associated with accessory navicular, Paralytic (spastic and flaccid) flatfoot. 

Soft flat feet that have arch with non - weight (above) and no arch with weight (below)
(Ref: https://www.semanticscholar.org/paper/Clinical-examination-of-the-foot-and-ankle.-Young-Niedfeldt/29bf0a47859ba614110d2e17270f54d503930fcf)

Evolution of foot arch

We have seen that every baby does not have a foot arch, maybe, because the baby's age is not about time to stand and walk. Standing, walking, running, or jumping have to be supported by feet that human feet have important roles in supporting, moving and balancing the body. The feet must not only support the weight of the body but must also have the elasticity to absorb the burden associated with supporting an excessive body weight. Foot elasticity is a function of the arched shape of the foot and the associated bone, ligament, tendon, and muscle structures, which form what is called the foot arch. 

The medial longitudinal arch typically starts to develop around the age of 2 years with development continuing until age 6 - 10 years, at which point approximately 20 - 25% of individuals remain flatfooted. Most children’s feet are, and remain, pain free whether or not they develop a longitudinal arch. Some young children with physiologic flatfeet present with bilateral non- localized activity - related and/or nocturnal foot and/or leg pain without any findings of redness, swelling, tenderness, or warmth. Early fatigue and rapid shoe breakdown may be reported.

Baby feet 
(Ref: https://www.bioped.com/)

In 90% of the children aged older than 2 years, an anatomic variation resembling flatfoot can be seen which is due to infantile adipose cushion formation localized on the medial part of the foot. Besides, toddlers who start to walk can assume a flatfoot posture. In fact they try to walk with their feet resting entirely on the ground so as to maintain a balanced posture. Consequently, they shift their weight-bearing axis to the first or second tarsometatarsal joint which may induce a flatfoot posture. In most of the children normal longitudinal arch develops at 3 - 5 years of age, and in only 4% of them flatfoot persists after 10 years of age.

Child feet
(Ref: https://www.doreenfac.com.au/)

In nearly 23% of the adult population collapse of the medial longitudinal arch of the foot can be seen. However it is not an isolated entity, and in 2/3 of the cases, subtalar complex, hyperflexible ankle joint, and in one-fourths contracture of the triceps surae muscle have been observed. Probably these combined pathologies cause patients’ complaints rather than collapse of the medial longitudinal arch.

Prevalence of flat feet varies with age, type of population and the presence of comorbidities. Flat feet have been associated with family history, wearing footwear during childhood, urban residence obesity, age, gender, BMI, and foot length. Flat feet could also be secondary to various conditions, such as ligament laxity, Rheumatoid arthritis, Diabetes, foot or ankle injury, posttraumatic arthritis, peroneal spastic flat foot, Charcot foot and posterior tibial tendon dysfunction. These factors can develop flat feet change in adults and elders, especially in high BMI groups.  

Overweight feet
(Ref: https://policyinpractice.co.uk/)

Pathoanatomy/Biomechanics of Flatfoot Deformity

 the subtalar joint complex (STJC), recognizing that the talo-calcaneal joint (the true subtalar joint) is the most important joint, and the location of all major foot deformities that can only move in combination with the talo-navicular joint.  

The axis of motion of the STJC is a constrained ball and socket-type joint that rotates three-dimensionally around a fixed oblique axis. Imagery between subtalar joint and hip joint, in the hip, the femoral head rotates within the acetabulum. In the subtalar joint, the acetabulum pedis (socket), which comprises the navicular, the anterior and middle articular facets of the calcaneus, and the spring ligament, rotates around the talar head (ball). 

Subtalar joint complex (Blue line) (Ref: https://ankleandfootcentre.com.au/)

More recently, the concept of the acetabulum pedis (AP) has been expanded to develop that of the calcaneopedal unit (CPU), which is a term used to describe the entire foot including that beyond the acetabulum pedis or subtalar joint complex. All major foot deformities, including flatfoot, have rotationally opposite static deformities within the CPU in relationship to the subtalar joint deformity. In flat feet, the hindfoot assumes a valgus position with eversion of the STJC, or more accurately, external rotation, dorsiflexion, and pronation of the AP/CPU around the talus. In flatfoot, the rotationally opposite direction deformity within the CPU is supination. These rotationally opposite direction deformities enable a flatfoot to maintain a plantar-grade tripod configuration. Valgus/eversion (pronation) of the hindfoot with rotationally opposite direction supination of the forefoot enable weightbearing on the plantar-medial corner of the calcaneus and the first and fifth metatarsal heads. 

The hindfoot assumes a valgus position with eversion of the STJC in flat feet (Left). Contrast with high arch shows a varus position (Right) (Ref: https://www.pinterest.com/)

Among those structures, the medial longitudinal arch (MLA) of the human foot has multiple functions, including absorbing and distributing load forces and providing stability. However, if the MLA structure collapses, which may be due to various causes such as posterior tibial tendon dysfunction or tight gastrocnemius soleus complex, a flat-foot condition occurs. In flat - foot cases, downward forces are deflected toward the inside of the foot, including the forefoot and the medial column, due to excessive pronation (hyperpronation).

Medial longitudinal arch (Upper), Lateral longitudinal arch (middle), Transverse arch (lower)
(Ref: https://epos.myesr.org/)

The 3 lesion levels of flat feet pathophysiology are the talonavicular, tibiotarsal and midfoot joints. The subtalar joint is damaged by the consequent rotational defects. Clinical examination determines deformity and reducibility, and assesses any posterior tibialis muscle deficit, the posterior tibialis tendon and spring ligament being frequently subject to degenerative lesions. 

Flat feet clinical presentation

Many people with flat feet are asymptomatic or never have trouble. By theory, however, the deformities concomitant with flat feet may cause pain, instability, uneven plantar pressure distribution, gait problems and foot fatigue which may have a significant influence on daily activities. All these changes can subsequently lead to slower walking speed, decreased stride length and cadence and increased stance duration all of which reduces functionality and overall well - being. The features of flat feet are an extremely low arch that increases the risk of hallux valgus, hammer toes, patellofemoral pain, and other musculoskeletal complications including low back pain. 

Flatfoot is considered pathological only when symptomatic. Pain is generally located in 

the medial part of the hindfoot, along the posterior tibial tendon, sometimes associated with effusion into the tendon sheath. Pain may be plantar and deep, suggesting spring ligament lesion. Even so, such pain may be caused by another pathology, such as talocalcaneal synostosis coalition or talonavicular, subtalar or mediotarsal osteoarthritis. Pain may also be lateral, due to fibulocalcaneal impingement in severe tibiotalar valgus, calcaneocuboid impingement in severe forefoot abduction, or impingement between the lateral tubercle of the talus and dorsal angle of Gissane of the anterior apophysis of the calcaneus in case of rotation and slippage of the talus.

The posterior tibialis tendon and spring ligament (Ref: https://coa.org/2017/presentations/Sunday/8SitlerDavidUpdate2.pdf)

Fundamental of flat feet treatment

3 majors treatment of flat feet consists of operative, insole, and exercises. The golden period of children must be before 6 years old and not greater than 10 years old. In physiotherapy, we have always suggested arch support insoles and exercise that focus on exercises. 

Flatfoot exercises are analyzed in two main headings: weight - bearing, and non - weight -  bearing exercises Exercises performed while seated are non - weight - bearing exercises which include rotating the feet, trying to grip the objects on the floor with foot, holding knees, and feet in extension, forcing the toes for abduction, and adduction, and crossing one foot over the other. Similarly, walking on tiptoes or on the outside edge of the foot, standing on tiptoes on an elevated surface, and walking with flexed feet are some of the weight - bearing exercises. If contracture of the Achilles tendon is present, stretching exercises, and Thera - Band exercises should be performed by the parents or if compliant by the patients themselves. 

Toe standing and walking
(Ref: https://lermagazine.com/)

 

Reference: 

https://jag.journalagent.com/nci/pdfs/NCI_1_1_57_64.pdf  

https://www.dovepress.com/the-prevalence-and-factors-associated-with-low-back-pain-among-people--peer-reviewed-fulltext-article-IJGM  

https://www.jposna.org/index.php/jposna/article/view/112  

https://www.ijhsr.org/IJHSR_Vol.10_Issue.2_Feb2020/30.pdf 

https://www.jfasap.com/doi/JFASAP/pdf/10.5005/jp-journals-10040-1149 

https://www.sciencedirect.com/science/article/pii/S1877056814003314 

http://aassjournal.com/article-1-929-en.pdf 

Flat feet vs. Neutral vs. High arch. How to do footprint yourself to classify your type of foot arch?

 

Wet footprint by water or sweat on the floor
(Ref: https://www.apexfoot.com/blog/)

    I think, either you have been mentioned to someone flatfeet or you were asked about your flatfeet from someone. According to this conversation, it is discussed about abnormal foot posture and many bad conditions from the abnormal foot posture. Have you questioned this kind of conversation? Are you flatfeet? Does it always trouble your quality of life? 

    I always observe the foot arch characteristic as routine physical assessment in patients with foot pain, ankle pain, knee pain, low back pain, mid back pain, or neck pain. I realize that the foot is the base of every standing posture and activities, and is the origin of posture alignment. 

Dropped foot arch develop poor posture and joint alignment (left)
(Ref: https://www.painfreeatsea.com/new-blog/)

The human feet are very complex having different components working together to create a complex flexible structure. The foot forms an important support for the body including support, balance, and mobility to the body. The foot arch is important in lifting the body weight and shock absorption by the ground reaction forces, which makes the arch a very important factor on walk and run safety, thus making direct influence on the biomechanics of an individual in case of any change. 

There are two main functions for the foot during walking: a passive function which protects the human body from impact forces and an active function to transfer internal forces to the ground. The medial longitudinal arch (MLA) of the foot is the primary shock-absorbing structure particularly important for foot function . 

Longitudinal arch load - shearing of the foot
(Ref: https://www.sciencedirect.com/science/article/pii/S0210123817300087)

    Foot arch types can be classified by the Medial Longitudinal Arch (MLA) as high arch (cavus foot or oversupinate), normal arch (rectus foot) or low arch (planus or flat foot or overpronate). Both flat feet and high arch feet do not transmit forces efficiently and might lead to foot diseases. 

    My foot arch evaluation and posture is observation by vision mostly because some patients were obviously characteristic of heel and arch position. By the way, I cannot indicate them in some cases clearly. So, I have to use simple equipment and measure techniques for assessment that you can do yourself at home as well.

Ref: https://www.eastcoastpodiatry.sg/blog-post/

The technique to measure rear heel posture

VIDEO #1: We need a small goniometer or semicircular protractor, a small ruler, and a pen. Patients stand on the steps in order to easily see the heel and calf. Heel and calf are marked by a pen that the first mark is mid rear heel - the second mark is mid achilles tendon at malleolus level - the third mark is mid calf muscle. Then, I draw a straight line connecting all of them. After that, I use a goniometer or semicircular protractor to measure the angle. 

“The normal range of rear heel posture is between 0 - 5 degrees”. 

If the outcome is greater than 5 degrees either heel abduction or adduction, it will be indicated abnormal rear heel posture. Normally, foot arch type is related to rear heel posture. The flatfeet is always associated with an abducted heel that the high arch is opposite. 

The footprint technique to classified foot arch type 

    VIDEO #2: Footprint: We need some black colored papers, powder, and a ruler. I started to put a lot of powder on a full plantar’s patient sitting position on the chair. Then I asked the patient to stand on the black paper for a while, and sit down to finish the footprint.

            VIDEO #3: Calculation and analysis to classified: Then I selected one technique analysis to calculate the foot arch index, including:

(1) Arch (Clarke) angle: This is the angle between the line connecting the medial side-most points of the heel and metatarsal regions and the line connecting the lateral most point on the medial foot border to the medial-most point of the metatarsal region. perspective error. 

Arch Clarke angle
(Ref: https://www.dovepress.com/)

The Clarke angle was calculated by Clarke index (ABC angle) which is Point A is the angle at the medial most margin of the forefoot, point B connects the medial side of the foot to the medial most part of the metatarsal region and point C at the medial most margin of the hindfoot.

The arches are defined based on scores of ABC angle; high arch (46 - 66 deg), normal arch (31 - 45 deg) and flat arch (10 - 30 deg).

(2) Chippaux-Smirak index: This is the ratio of the minimum width of the midfoot arch region to the maximum width of the forefoot region. They consist of a CD line at midfoot width and AB line at forefoot width. It is calculated by “(CD/AB) x 100” that the arches are categorized as high arch (10% - 24%), normal arch (25% - 45%) and flat arch (46% - 70%). 

CD/AB ratio in Chippaux - Smirak index
(Ref: https://biomedical-engineering-online.biomedcentral.com/articles/10.1186/s12938-022-01021-7)

(3) Staheli index: This is the ratio of the minimum width of the midfoot arch region to the maximum width of the rearfoot region. It is calculated by “CD/EF” that line CD is the narrowest width of the midfoot and line EF is the wider zone of the hindfoot. The arches are defined as; high arch (0.1-0.4), normal arch (0.5-0.7) and flat arch (0.8-1.2).

CD/EF ratio in Staheli index
(Ref: https://biomedical-engineering-online.biomedcentral.com/articles/10.1186/s12938-022-01021-7)

(4) Arch length index: This is the ratio of the length of the line between the medial area -most points of the metatarsal and heel regions to the border length of the arch outline between these points.

Arch length index (Left)
(Ref: https://www.researchgate.net/figure/Definitions-of-foot-arch-parameters-a-arch-index-AI-measurement-from-the-footprint_fig1_318915682)

(5)  Arch index: This is the ratio of the “area” of the middle third of the toeless footprint to the overall toeless footprint area. A line is drawn between the center point of the second toe and the posterior-most point on the heel. Two parallel lines perpendicular to this line are drawn to divide the toeless footprint area into equal thirds. 

It is calculated by “(C+D+E)/D” that Line AB connects from the area of the forefoot at point of 2nd toe (toeless area) to the medial point of hindfoot. Line AB was divided into three equal areas of foot as C (covers most areas of forefoot), D (area of midfoot) and F (medial area of hindfoot). Arch index was calculated as the ratio between the sum of areas C, D and E over area D. 

Arches are categorized based on scores obtained from the ratio of areas; high arch (0.11-0.20), normal arch (0.21-0.28) and flat arch (0.29-0.38).

Arch index (Right)
(Ref: https://www.researchgate.net/figure/Definitions-of-foot-arch-parameters-a-arch-index-AI-measurement-from-the-footprint_fig1_318915682)

(6) Footprint index: This is the ratio of the non-contact area to the contact areas of the toeless footprint. The non-contact area is the area between the medial borderline axis formed by the medial-most points of the metatarsal and heel regions of the footprint and the medial border of the footprint outline. The contact area is the area of the toeless footprint.

(7) Truncated arch index: This is the ratio of the non-contact area (the arch area) to the truncated footprint area. The non-contact area is the area between the medial border line and the medial footprint outline. The truncated footprint area is bounded by the area between the lines perpendicular to the medial borderline. 

Middle lower demonstrates footprint index,
Right lower demonstrates Truncated arch index
(Ref: https://www.researchgate.net/figure/a-f-Graphical-illustrations-of-the-various-footprint-parameters-Arch-Clarke-angle-a_fig1_235779400)

In fact, there are several techniques for classification of foot type that are described in the literature, which measure the morphology and foot posture in a static position or during locomotion. Within the morphological classification techniques of the foot when standing are: visual inspection non-quantitative, anthropometric values, footprint parameters, radiographic evaluation, foot scan. Among these types of techniques there are pros and cons to all of them, as well as subjectivity and dependence of the experience of the evaluator (visual assessment techniques or by palpation) or expensive costs such as for the radiographic techniques.

Footprint scan
(Ref: https://jfootankleres.biomedcentral.com/)

    Various techniques are used to determine these indices, including observation, foo printing, pressure mapping, radiographic imaging, ultrasound imaging, navicular drop, angle - related, foot function, etc.

High arched feet allow less motion and are identified as a risk factor for lateral ankle injury, stress fractures, and anterior knee pain. The most cases that I have seen was plantar fasciitis that was more than in flat feet. 

While low arched feet have been shown to be at increased risk for medial tibial stress syndrome, knee pain, and other injuries involving the medial and soft tissue structures of the lower extremity. The most cases that I have seen complained about anterior knee pain and lateral knee pain which was ITB syndrome.

foot arch type and shoes wore
(Ref: https://www.solescience.ca/)

The survey studies tell us that excessive increase in weight bearing forces caused by obesity may adversely affect the foot arches. Elderly people have shown to have flatter, longer and wider feet than younger adults, and also older adults with osteoarthritis show greater dynamic loading of the midfoot when walking, due to the lower arch. A gender differences study showed that women have less arch stiffness than males and their arch is more flexible under both static and dynamic weight-bearing conditions. 

It does not matter what factor you have, if you take care of your arch of foot well enough such as proper running shoes, proper insoles, proper sports & exercises, control BMI, etc., you will have a good quality of life.  

Running shoes type for foot arch type
(Ref: https://www.pinterest.com/)

Reference:

https://www.scielo.br/j/clin/a/NDfBndMWPC3J5XPchrJKPmK/?lang=en&format=pdf

https://www.semanticscholar.org/paper/Foot-arch-characterization%3A-a-review%2C-a-new-metric%2C-Xiong-Goonetilleke/7344ceb3777c2fafb8b67bfc8ba0858e111359e1

https://www.researchgate.net/publication/235779400_Evaluation_of_the_sole_morphology_of_Professional_football_players 

https://www.jospt.org/doi/pdf/10.2519/jospt.2006.2336 

https://ph02.tci-thaijo.org/index.php/JIST/article/view/243495 

https://www.rehabilityjournal.com/articles/jnpr-aid1005.pdf

https://journals.indexcopernicus.com/api/file/viewByFileId/291325.pdf

http://www.ukm.my/jsm/pdf_files/SM-PDF-46-10-2017/22%20Shaliza%20Mohd%20Shariff.pdf

Physiotherapy with (second) 10 of 20 lateral abdominal basic exercises for low back pain (ep.2)

Side abdominal exercise
(Ref: https://excelfitindia.com/)

    The lateral abdominal muscles including transversus abdominis (TrA), internal oblique (IO), and external oblique (EO). All of the trunk muscles are considered to be important for the restoration of normal function and progression involves strategies for re-education of the whole muscle system.

Refer to the recent topic which talks about lateral abdominal and spine movement that indicated multi - muscle in one movement. Torso rotation is associated between the same IO side and opposite EO side. Torso side bending acts by the same side of IO and EO and TrA. Torso forward bending such as sit up is moved by EO anterior fibers, TrA, and rectus abdominis. Abdominal flattening is developed by TrA and EO. 

Side bending exercise
(Ref: http://www.jasestuart.com/)

The second basic 10 of 20 therapeutic strengthening exercises to activate lateral abdominal muscle for low back pain (Remark: If you feel severe pain and any numbness or significant weakness, I would like to recommend you to stop exercising and observe the symptoms. And consult your physiotherapist or doctors.)

 

Each exercise needs 10 - 15 reps with 3 sets for 3 - 5 days a week. (Remark: Keep breathing during exercise for more efficiency because the diaphragm is a member of core stabilizer muscles.)

Exercise #11: Heel tap

Exercise #12: Quadrup spider

Exercise #13: Spider

Exercise #14: Lower torso rotate

Exercise #15: Upper torso rotate (Russian twist)

Exercise #16: Basic crunch

Exercise #17: Lateral crunch

Exercise #18: Rotation crunch

Exercise #19: Cross crunch

Exercise #20: Easy starfish crunch

 

A contemporary approach for LBP involves recruitment of TrA which contributes to lumbo-sacral stability by its role in intra-abdominal pressure, creating tension of thoraco-lumbar fascia, and compression of sacroiliac joints. It produces little force for trunk flexion, extension and lateral flexion. Despite its involvement in rotation of the trunk, it has only a small lever arm to produce rotational movement. 

These exercise approaches need minimal activity about 2% - 3% of maximum voluntary contraction of the superficial abdominal muscles in the early stages of rehabilitation. To stimulate TrA activity based on evidence based practice  contributes to spinal control and dysfunction of this muscle occurs in people with LBP.

Intra - abdominal pressure support low back spine
(Ref: https://www.performancehealthcarepdx.com/)

The recruitment of TrA is emphasized initially as abdominal hollowing (AH) maneuver or abdominal bracing has been presented as an activity which exercises the TrA muscle in an isolated fashion. It recruits OE with less activity of upper TrA, lower OI and RA. The technique involves inward movement of the lower abdominal wall without movement of the spine or pelvis.

  In order to control the contraction of TrA during this maneuver, palpation of its tendon medial to anterior superior iliac spine, and also Pressure Biofeedback (PBF) have been used. The efficacy of this method has been established in randomized control trials with acute and chronic LBP patients.

Surface anatomy of core stabilizer muscle palpation at
her index and middle finger where are above iliac crest.
(Ref: https://depositphotos.com/)

The 'curl-up' exercise in supine used to strengthen the abdominals, especially rectus abdominis, is a good example of this type of strengthening exercise. Producing a force or torque which can be used for specific movements is only one aspect of muscle function. It is similar to McGill that uses it to strengthen the EO majorly.   

The pelvic tilting is likely to produce greater activity of middle OI relative to upper TrA and RA.  

One musculature mechanism which involves stability is the production of tension in the lumbar dorsal fascia. Upper fascicles of TrA that attach to the rib cage are horizontal, and middle and lower fascicles that fuse with the thoracolumbar fascia and the iliac crest are inferomedial. Fibers of upper TrA are also active with the opposite direction of trunk rotation to lower and middle fibers, and activity of lower and upper fibers of OI vary during posterior pelvic tilting.

Left to right: TrA - IO - EO - Thoracolumbar fascia
(Ref: https://www.crossroadsphysiotherapy.com/)

            The lumbar dorsal fascia is a noncontractile structure which provides considerable support to the lumbar area. Its contribution to stability is increased through the influence of muscle attachments.  Tension in the fascia can be increased by contraction of the internal obliques and transverse abdominals which attach to the middle layer of the fascia. Tension is also increased between the middle and posterior layers of the fascia by the contraction of the paraspinal muscles. Although the lumbar dorsal fascia provides local protection fur the lumbar spine, it appears that increasing intra-abdominal pressure(IAP) could provide a more general mechanism for protection of the whole spine.

Ideal posture (Left) & Lower cross syndrome (Right)
(Ref: https://evergreenclinic.ca/)

Many muscles worked in synergistic groups and appeared to be specifically involved in mechanisms designed to stabilize, protect the lumbar spine and control neutral posture. For example, weakness of OE causes sway back posture which is thoracic behind the pelvic. Or Hyper lumbar lordosis posture because of TrA weakness. 

You can watch more VIDEO on https://yimphysionearme.blogspot.com/2022/09/physiotherapy-with-9-of-18-basic.html and https://yimphysionearme.blogspot.com/2022/09/the-second-physiotherapy-with-9-of-18.html 

 

 

 

Reference: 

https://core.ac.uk/download/pdf/227985494.pdf 

 

https://www.researchgate.net/publication/23480146_Altered_response_of_the_anterolateral_abdominal_muscles_to_simulated_weight-bearing_in_subjects_with_low_back_pain

 

https://www.sciencedirect.com/science/article/pii/S0004951414605146

 

http://www.pnfchi.com/fotos/literatura/1233770497.pdf

 

https://d-nb.info/1114223050/34

 

Kendall FP., et al. Muscles testing and function. Fourth edition. Williams & Wiikins. USA.

1993.