Effects of 8-weeks Systematic Corrective Exercise Program in Pronation Distortion Syndrome

Pronation distortion syndrome is a common postural distortion of the lower extremity, involving the anterior part of the leg. In this deformity, the head of the talus and navicular bones are rotated inward and downward, and the body's center of gravity shifts inward, resulting in flat feet. It may cause pain in the leg and disturbances in the tarsal part, in addition to distal and proximal parts. Excessive foot pronation include inward rotation of the tibia, internal rotation of the thighs associated with flat feet, genu valgum (knock-knee), and increased lordosis thus causing abnormalities in lumbo-pelvic region and lower limb.

In this deformity, peroneal muscle, gastrocnemius muscle, hamstrings, soleus muscle, iliotibial band, adductors, and psoas muscle are functionally tightened, while posterior and anterior tibialis, gluteus Medius, gluteus maximus, vastus medialis, and hip external rotators are inhibited. Excessive pronation will misalign the entire lower body, reducing the ability of powerful muscles like the quadriceps and glutes to maintain force production. Length tension relationships establish that the resting length of a muscle determines whether it can generate optimal tension, if the feet excessively flatten and the femur excessively rotates and adducts, then the joints don't stack, the tissues don't load, and energy is lost. Over time, tissues may become irritated, inflamed or even weakened, which often leads to more serious problems, such as ruptured tendons or stress fractures . The body weight normally falls on the center of the foot, and balance is maintained by the muscle activity of the foot. If the foot becomes diseased or deformed, the foot adapts to perform its functions under the conditions of disease or deformity. Several factors of pronation distortion can increase the likelihood of cuboid syndrome including midtarsal instability, excessive body weight, ill-fitting or poorly constructed orthoses or shoes and inadequate exercise recovery. The postural defects cause pronated subtalar joint, inverted forefoot and instability of mid tarsal joint leading to improper dynamic stabilization. Every degree of subtalar pronation that occurs produces an exponential increase in midtarsal joint instability. Pronated feet are very common among people with flexible flat feet in which the medial longitudinal arch of the foot largely collapses during the stance phase of gait causing over supination and over pronation but restores after removal of body weight. Kinetic coupling of 4 pronated feet alters during improper gait mechanics and results in changes of inter joint angle coordination. This disturbs the inter joint coordination which is involved in determining movement flexibility and stability thus effecting gait pattern leading towards occurrence of injury. In the case of postural distortion, instability and damage to the lower extremity cause hypermobility, and passive instability and more neurological control by the neuromuscular system is required to maintain stability and balance. The instability resulting from a flat foot could cause patho-mechanical problems as well as a compensating action in the close kinematic chain of the lower extremity. Excessive pronation transmitted to internal rotation of the tibia, may cause overloading of the knee joint or may be the cause of other changes in proximal part of the lower extremity. The feet support the body's weight and play the role of levers when an individual is performing work. By performing closed kinetic chain exercises under loads and by increasing the strength of the muscles proximal to the lower extremities, one can correct the hyper pronation of the foot in the distal lower extremities and can prevent ligamentous laxity. This study will determine the effects of 8 weeks systematic corrective exercises on body posture and stability in pronation distortion syndrome. PDS is a postural defect that occurs by initiation of foot hyper pronation that further causes forced tibial rotation, knock knees and progression of lumbar lordosis. Studies suggest women are more prone to pronated feet than men recording prevalence of 20-30 percent.

Furthermore, biomechanical abnormalities reported to be prevalent as 60-90 percent.

In 2020 Ali Golchin et al conducted a study to emphasize on the postural deformities caused by pronation distortion syndrome. It was a randomized controlled trial. In this study functional movement screening were performed to evaluate subjects' performance. Treatment protocol included systematic and corrective exercise program that concluded reduction in likelihood of injury and improvement in posture with subjects with pronated feet.

In year 2020 Marina gil-calvo et al studied the effects of custom-made and prefabricated foot orthoses on kinematic parameters in recreational runners with flat feet dysfunction.

Initial field test was monitored to determine individuals maximum aerobic speed in athletes.

Subjects with history of foot orthosis implementation were excluded. There were three groups, one with custom orthosis, 2nd group underwent with prefabricated orthosis and 3 rd was control group. Foot eversion parameters were measured before and after the intervention.

Findings of the study suggested no significant difference in improvement even after weeks of intervention. Modification in the running mechanics to maintain ideal movement pattern in runners were suggested for better outcome . In 2020 Manuel Pabón-Carrasco et al checked the association of short foot exercises (SFE) with Non biomechanical function (NBF) exercises in the strength development of intrinsic muscles of pronated feet. The intrinsic foot muscle is considered primordial in maintaining the plantar arch and controlling foot posture. A randomized clinical trial was carried out with 85 asymptomatic participants with a bilateral Foot Posture Index (FPI) greater than 6 points.

The pronation of each foot were measured twice. Changes were observed in the ND and FPI pre-intervention and post-intervention for the subjects of each independent group. A tendency of a more neutral position and a decrease of the ND were noted. 6 In 2019, according to Nikkhouamiri F et al, postural abnormalities due to dysfunction of pronated feet can irritate the functional and balance kinematic of walking resulting in skeletal abnormalities and postural control disorder. Navicular drop test was used to asses the flat feet deformity. Given the results, application of corrective exercise program on improving balance and function in female population were effective. Female adolescents showed improved postural control, coordination and stability. Farhan Alam et al in 2019, worked on selective strengthening of tibialis posterior and stretching of iliopsoas on navicular drop, dynamic balance, and lower limb muscle activity in pronated feet. A previous study reported that 20% of the adult population have flatfeet and 12.8% of adults with flatfeet are males and 14.4% are females. The experimental group performed stretching and strengthening of tibialis anterior, iliopsoas and adductor muscles whereas conventional group performed towel curl exercises. Improvement in biomechanical alignment was noted in this study. Ru-Lan Hsieh, MD et al in 2018, conducted a randomized controlled trial study to measure the effects of customized arch support insoles in children with flexible flat and pronated feet.

In this 12-week intervention program subjects went through the measurement of calcaneal inclination angle; hypermobility score and navicular drop test. Physical activity i.e., 10-m normal and fast walking, stair ascent, stair descent, and chair rising were assessed within the intervention. The insoles helped subtalar joint to maintain its normal neutral position during mobility (14). The literature suggests to conduct a study on both males and females with age group more than 16 years. There has been studies that has worked on foot for correction of pronation but the correction of kinetic chain disturbance due to hyper pronation has been in neglection. Given the prevalence of flat feet and influence of proximal and distal chains, this study will be conducted to determine effects of 8-Weeks Systematic CCorrective Exercise program on Body Posture and stability in Pronation Distortion Syndrome.