Relationship Between Flexible Flat Foot and Lumbar Proprioception

The human foot plays a crucial role in maintaining balance during various activities, and poor foot alignment, such as excessive subtalar joint pronation, can lead to leg, knee, and back pain. Proprioception is essential for active joint stability, as it indirectly modulates and provides motor response, helping the neuromuscular system maintain balance. Lumbar proprioception deficits can decrease the ability to assume a neutral spinal posture and coordinate muscle contraction, affecting spinal segmental function, dynamic joint stability, and good motor control. This study investigates the association between flatfoot and lumbar proprioception.

Primary outcomes

• assessment of the foot posture using navicular drop test [at baseline]: The study evaluates foot posture in a weight-bearing position by placing the thumb and index fingers on the medial and lateral aspects of the talar dome. The subject is then asked to invert and evert the hind-foot and ankle until equal depressions are felt. The distance between the navicular tubercle and the floor is measured. The navicular-drop score is recorded, and the subject is classified into a pronated foot (more than 10 mm of navicular drop) and a normal foot (between five and nine mm of navicular drop).

Secondary outcomes

• assessment of change of lumbar proprioception using Biodex system isokinetic dynamometer [at baseline]: The Biodex System 3 Pro isokinetic device is used to measure lumbar proprioception. The device offers isokinetic, eccentric, isometric, and passive modes for all body joints and is equipped with various attachments and isolation straps. The system is equipped with a computer unit and a special testing unit for lumbar area testing. Subjects are instructed to sit on the lumbar attachment unit with their hips and knees flexed at 90 degrees, strapped around their thigh, pelvis, and trunk, and fold their arms above their chest. The selected test is active repositioning error/speed 30o/S, with a target position of 30° lumbar flexion. The device is locked in 0° position during trials, and the isokinetic device software calculates the mean of the three real testing results. The isokinetic machine prints the results, providing each trial's error value and the average error of the three trials.

Sex: All, ages: 17 Years to 35 Years

Inclusion Criteria:

* 60 subjects of both sexes (females and males) were selected and assigned into two groups
* Patient's age range was between 17 to 30 years old.
* Subjects with flexible flat foot posture according to the Navicular Drop Test by Brody method: a normal foot (between five and nine mm of navicular drop), pronated foot (more than 10 mm of navicular drop).
* Patients will be willing and able to participate in assessment without cognitive impairments that would limit their participation

Exclusion Criteria:

The potential participation was excluded when they had one of the following criteria:

* Repeated lower extremity injuries, such as fractures or deformities.
* History of surgery to the lower extremity.
* history of back surgery
* rheumatologic disorders
* spine infections
* ankle fracture
* lumbar fracture
* spondylosis
* lumbar disc bulge
* spondylolisthesis