Balance, Plantar Pressure Distribution and Gait in Pes Planus
Condition: Pes Planus
MeSH terms: Flatfoot
Study type: Interventional

Summary: 
      Introduction:The results of studies evaluating balance, plantar pressure analysis, and gait
      in adults with pes planus have differed in the literature. The aim of this study is to
      evaluate balance, plantar pressure, and gait in adults with pes planus and compare them with
      adults without pes planus.

      Materials and Methods: The study will be conducted at the Ministry of Youth and Sports,
      Athletic Training and Research Center. A total of 118 individuals, 59 individuals with pes
      planus and 59 individuals without pes planus, will be included in the study according to the
      Navicular Drop Test and Foot Posture Index. In the study, the descriptive characteristics of
      the individuals will be recorded. Static and dynamic balance measurements, plantar pressure
      analysis and gait analysis of individuals will be performed, and the two groups will be
      compared.

      Results: The data will be analyzed using the statistical program for social sciences (SPSS)
      version 21.0 (IBM SPSS Statistics for Windows, Armonk, NY: IBM Corp.). The data will be
      expressed as mean standard deviation (X±SD) and number (n%). The homogeneity of the groups
      will be evaluated with the Levene Test. Balance, plantar pressure, and walking values between
      the groups will be compared using the "Mann Whitney-U" Test. All the statistical analyses
      will be set a priori at an alpha level of p<0.05.

      Discussion: The results will be discussed in the light of the recent literature. In the
      literature, there are conflicting results about the balance and gait of adults with pes
      planus. The study can contribute to the literature in this respect.
    

Detailed description: 
      Introduction The lower extremity kinematic chain includes foot, ankle, knee, and hip joints.
      The foot is a complex structure and provides the body's contact with the ground. The foot is
      one of the most important sources of somatosensory information required for balance and
      walking. The proprioceptive information from the joints, muscles, and ligaments of the foot
      maintains the upright posture. Also, it helps to absorb ground reaction forces during walking
      and provides balance by adapting to different grounds.

      The arches of the foot have a critical role in stability and flexibility. These arches have
      functions such as carrying body weight, contributing to the gait cycle, and generating
      energy. The foot has two longitudinal arches in the transverse plane: the medial longitudinal
      arch and the lateral longitudinal arch. The calcaneus, talus, navicular, cuneiform I, II,
      III, and the first three metatarsal bones form the medial longitudinal arch. The arch is the
      primary weight-bearing and shock-absorbing structure of the foot. The talonavicular joint,
      the subtalar joint, and the tibialis posterior muscle protect the structure of this arch.

      Pes planus is defined as the decrease or complete disappearance of the medial longitudinal
      arch of the foot. It is the most common deformity among foot deformities. All babies have pes
      planus on their feet from birth. The medial longitudinal arch may not form in the feet of
      healthy infants until the age of 3 years. In advancing age, the development of the midtarsal
      joints and bones is supported by the strengthening of the ligaments, and the medial arch
      develops. However, with the weakness of the plantar fascia and muscle groups that support the
      medial longitudinal arch, arch support may decrease, and pes planus may be seen. In addition,
      it can be seen as a result of excessive load on the plantar fascia in adults who stand on
      hard floors for a long time due to their profession, in obese individuals, in cases with
      muscle imbalance, or as a result of the progression of pes planus in childhood. In a study on
      pes planus and pes cavus; 60% of the population had a normal foot structure, while 20% had a
      pes planus foot structure, and 20% had a pes cavus foot structure.

      Pes planus causes a change in the load distribution in the medial side of the foot. The
      number of loads on the lower extremity joints and lumbar vertebrae vary. Various symptoms are
      seen after this biomechanical change. The symptoms are pain, loss of strength, fatigue,
      instability, and functional limitations, especially with walking and standing. As a result of
      the energy expenditure of the individuals during gait also increases. The increased energy
      expenditure negatively affects lower extremity performance .

      Balance is the ability to keep the body's center of gravity within the acceptable limits of
      the support surface during activities such as sitting, standing, or gait. Balance is a
      complex process involving multifaceted sensory, motor, and biomechanical components. It is
      divided into two as static and dynamic balance. Changes in the normal alignment of the foot
      in pes planus cause abnormal sensory input from the foot, which prevents proper muscle
      activity required for posture and postural swings. This condition may cause balance problems.
      While some studies in the literature have shown that static postural stability, which is
      evaluated by force plate or balance systems, decreases in individuals with pes planus, others
      reported no difference compared to the neutral foot. Kim et al. stated that static stability
      is better in individuals with pes planus than in individuals without pes planus. The authors
      also found that there was no difference in dynamic stability. Plantar pressure distribution
      is a factor that affects both balance and gait. It has been observed that individuals with
      pes planus give more weight to the big toe, middle of the forefoot, and medial foot compared
      to the neutral foot. However, in another study, the same researchers compared pes planus, pes
      cavus, and foot pressure center in normal feet and found that only the terminal phase of the
      stance and the pre-swing phase differed. Although some evidence of characteristic plantar
      pressure patterns has been identified, differences in gait analysis protocols and plantar
      pressure analysis techniques make it difficult to obtain a clear result.

      The gait cycle is affected by many pathologies. Some factors such as deformities, loss of
      muscle strength, decreased motor or sensory control, balance problems adversely affect the
      gait cycle and cause gait disturbance. As a result, compensatory movements occur. Pes planus
      may also affect the gait cycle. It has been found that pes planus can cause the foot to go
      pronation and plantar flexion, adduction of the talus, and valgus of the calcaneus during
      load-bearing to the extremity. Hunt et al. performed a kinetic and kinematic analysis in the
      stance phase of walking in individuals with pes planus. However, the investigators found no
      difference between individuals with pes planus and the control group. The investigators
      stated that this result was due to the mild and asymptomatic pes planus of the individuals.

      All these biomechanical problems can lead to metatarsal stress fractures, plantar fasciitis,
      Achilles tendonitis, tibialis anterior inflammation, or patellofemoral joint pain in the long
      term. For this reason, it is necessary to evaluate pes planus from multiple perspectives and
      to recommend appropriate treatment approaches.

      As can be seen, the results of studies evaluating balance, plantar pressure analysis, and
      gait in adults with pes planus have differed in the literature. In addition, studies using
      objective computerized systems are few. The aim of this study is to evaluate balance, plantar
      pressure, and gait in adults with pes planus and compare them with adults without pes planus.

      Hypothesis 1:There is no difference between the static and dynamic balance values of adults
      with pes planus and without pes planus.

      Hypothesis 2:There is no difference between the plantar pressure distribution values of
      adults with pes planus and without pes planus.

      Hypothesis 3:There is no difference between the gait parameters of adults with pes planus and
      without pes planus.

      Methods Participants

      The university students and workers in Baskent University who meet the inclusion criteria
      will be contacted and invited to study. There will be two groups in the study:

      Study group -adults with pes planus Control group -adults without pes planus (normal foot)
      For the sample size calculation G*Power Ver. 3.0.10 (Franz Faul, Universität Kiel, Germany)
      was used. The sample size of the study was calculated with 85% power and 0.05 margin of
      error, and it was found that a total of 118 individuals, 59 individuals in each group, should
      be included in the study.

      Method In the study, the descriptive characteristics of the participants will be recorded.
      Then, by applying the Navicular Drop Test and the Foot Posture Index, participants will be
      divided into two groups as those with pes planus and those without pes planus.

      Navicular Drop Test The navicular drop test is one of the static foot assessment tool. The
      researchers will measure the distance between the navicular tuberosity and the ground with a
      caliper with non-weight bearing in sitting. After that, the distance between the ground and
      the navicular tuberosity will be measured in standing while weight-bearing. The researchers
      will evaluate both sides and record the value in mm. According to Navicular Drop Test, the
      difference between weighted and unweighted measurements is considered normal (neutral) if it
      is between 5 and 9 mm, pronation (pes planus) if it is 10 mm or more, and supination (pes
      cavus) if it is 4 mm or less. In the study, individuals with a difference of 10 mm or more in
      both feet will be included in the pes planus, and individuals with a difference between 5-9
      mm will be included in the control group.

      Foot Posture Index The index consists of six items in which the foot is evaluated
      observationally. In the evaluation, the individual is asked to stand in a comfortable and
      relaxed position. The researcher observes the medial longitudinal arch structure, the
      structure of the talonavicular joint region, the degree of abduction/adduction in the
      forefoot relative to the hindfoot in the front part of the foot. In the back foot,
      inversion/eversion of the calcaneus, talus head position, and curvatures above and below the
      lateral malleolus are evaluated. The total score is reached by scoring each criterion between
      -2 and +2 values. 0; neutral position, (+) values; pronation (pes planus), (-) values
      indicate supination (pes cavus). Individuals with +6 to +12 points from this index will be
      included in the study. Since this index is an evaluator-based scale, no Turkish validity
      study has been conducted.

      Balance Static and dynamic balance and stability limit values of individuals will be
      evaluated with the HUR Smart Balance (SME Inc, USA) balance measurement device. The device
      consists of a computer and a platform on which individuals can place their feet. For static
      balance measurement, individuals will be asked to place their feet on the marked places on
      the platform. The researchers will evaluate the balance in four different situations, 30
      seconds each. In the first test, individuals keep the balance on firm ground with their eyes
      open. The second test performed on the firm ground with eyes closed, in the third test, on
      the soft ground with eyes open, and in the fourth test, on the soft ground with eyes closed.
      For dynamic balance, individuals will be asked to extend their body weight to the front,
      back, and sides with their feet in 4 different directions for 8 seconds and reach the last
      point where the sole does not break with the ground. The device gives the balance value as a
      printout by calculating the deviation rate of the individual from the target and the risk of
      falling forward, backward, and sideways. The measurement takes an average of 10 minutes.

      Plantar Pressure Analysis Plantar pressure analysis of individuals will be evaluated by
      measuring with the DIERS Pedoscan DICAM 3 v3.10.8 (2019) device. DIERS Pedoscan is a system
      integrated into the treadmill that measures the pressure distribution on the sole during
      stance. As a result of this evaluation, right-left and anterior-posterior weight transfer,
      left-right foot rotation, lateral mobility, the center of gravity movement, and swing area
      data will be recorded.

      Gait Analysis Gait analysis of individuals will be evaluated with the DIERS Leg Axis DICAM 3
      v3.10.8 (2019) system. The system consists of a treadmill, computer, and cameras. Before the
      measurement, colored markers will be placed on the knee and ankle joints of the individual.
      For gait assessment, individuals will walk at their preferred comfortable walking speed. In
      the evaluation, joint angles, walking speed, step lengths are recorded. Evaluation time is
      approximately 5 minutes.

      Statistical analysis The data will be analyzed using the statistical program for social
      sciences (SPSS) version 21.0 (IBM SPSS Statistics for Windows, Armonk, NY: IBM Corp.). The
      data will be expressed as mean standard deviation (X±SD) and number (n%). The homogeneity of
      the groups will be evaluated with the Levene Test. Balance, plantar pressure, and walking
      values between the groups will be compared using the "Mann Whitney-U" Test. All the
      statistical analyses will be set a priori at an alpha level of p<0.05.

      Importance of the study In this study, researchers will expect that the balance, plantar
      pressure distribution, and gait parameters of adults with pes planus are different from
      healthy individuals. In the literature, there are conflicting results about the balance and
      gait of adults with pes planus. The researchers think that the study will contribute to the
      literature in this respect.
    

Intervention name(s): Navicular Drop Test; Foot Posture Index; Balance; Plantar Pressure Analysis; Gait Analysis
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): The researchers will measure the distance between the navicular tuberosity and the ground with a caliper with non-weight bearing in sitting. After that, the distance between the ground and the navicular tuberosity will be measured in standing while weight-bearing. The researchers will evaluate both sides and record the value in mm. According to Navicular Drop Test, the difference between weighted and unweighted measurements is considered normal (neutral) if it is between 5 and 9 mm, pronation (pes planus) if it is 10 mm or more, and supination (pes cavus) if it is 4 mm or less. In our study, individuals with a difference of 10 mm or more in both feet will be included in the pes planus, and individuals with a difference between 5-9 mm will be included in the control group.; The index consists of six items in which the foot is evaluated observationally. In the evaluation, the individual is asked to stand in a comfortable and relaxed position. The researcher observes the medial longitudinal arch structure, the structure of the talonavicular joint region, the degree of abduction/adduction in the forefoot relative to the hindfoot in the front part of the foot. In the back foot, inversion/eversion of the calcaneus, talus head position, and curvatures above and below the lateral malleolus are evaluated. The total score is reached by scoring each criterion between -2 and +2 values. 0; neutral position, (+) values; pronation (pes planus), (-) values indicate supination (pes cavus). Individuals with +6 to +12 points from this index will be included in our study.; Static and dynamic balance and stability limit values of individuals will be evaluated with the HUR Smart Balance (SME Inc, USA) balance measurement device. The device consists of a computer and a platform on which individuals can place their feet. For static balance measurement, individuals will be asked to place their feet on the marked places on the platform. The researchers will evaluate the balance in four different situations, 30 seconds each. In the first test, individuals keep the balance on firm ground with their eyes open. The second test performed on the firm ground with eyes closed, in the third test, on the soft ground with eyes open, and in the fourth test, on the soft ground with eyes closed. For dynamic balance, individuals will be asked to extend their body weight to the front, back, and sides with their feet in 4 different directions for 8 seconds.; Plantar pressure analysis of individuals will be evaluated by measuring with the DIERS Pedoscan DICAM 3 v3.10.8 (2019) device. DIERS Pedoscan is a system integrated into the treadmill that measures the pressure distribution on the sole during stance. As a result of this evaluation, right-left and anterior-posterior weight transfer, left-right foot rotation, lateral mobility, the center of gravity movement, and swing area data will be recorded.; Gait analysis of individuals will be evaluated with the DIERS Leg Axis DICAM 3 v3.10.8 (2019) system. The system consists of a treadmill, computer, and cameras. Before the measurement, colored markers will be placed on the knee and ankle joints of the individual. For gait assessment, individuals will walk at their preferred comfortable walking speed. In the evaluation, joint angles, walking speed, step lengths are recorded. Evaluation time is approximately 5 minutes.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Screening
Keywords: pes planus; balance; gait