Effects of Foot Core Exercises in Patients With Total Hip Arthroplasty

The muscle thickness of the foot and ankle periarticular structures will be evaluated using ultrasonography. Ultrasonographic examinations will be performed in accordance with the EURO-MUSCULUS/USPRM foot and ankle protocols (26, 27), using a Clarius ultrasound system (Clarius Mobile Health, 205-2980 Virtual Way, Vancouver, British Columbia, Canada) and a 4-13 MHz linear transducer. All measurements will be conducted by researchers who have received training in ultrasonographic imaging.

The muscle cross-sectional area of the foot and ankle periarticular structures will be evaluated using ultrasonography. Ultrasonographic examinations will be performed in accordance with the EURO-MUSCULUS/USPRM foot and ankle protocols (26, 27), using a Clarius ultrasound system (Clarius Mobile Health, 205-2980 Virtual Way, Vancouver, British Columbia, Canada) and a 4-13 MHz linear transducer. All measurements will be conducted by researchers who have received training in ultrasonographic imaging.

The MyotonPro device (Myoton AS, Estonia) will be used to evaluate the muscle tone (frequency) (F) of the gastrocnemius medialis (GM),gastrocnemius lateralis (GL) , tibialis anterior (TA), peroneus longus (PL) muscles, the Achilles tendon (AT), and the plantar fascia (PF). Frequency (F) characterizes muscle tone and is reffered as Hz (Hertz). All measurements will be performed on both extremities. To ensure standardization, appropriate anatomical reference points for each structure will be marked prior to measurement

The tendon morphology of the foot and ankle muscles will be evaluated using ultrasonography. Ultrasonographic examinations will be performed in accordance with the EURO-MUSCULUS/USPRM foot and ankle protocols (26, 27), using a Clarius ultrasound system (Clarius Mobile Health, 205-2980 Virtual Way, Vancouver, British Columbia, Canada) and a 4-13 MHz linear transducer. All measurements will be conducted by researchers who have received training in ultrasonographic imaging.

The MyotonPro device (Myoton AS, Estonia) will be used to evaluate the stiffness (S) of the gastrocnemius medialis (GM),gastrocnemius lateralis (GL) , tibialis anterior (TA), peroneus longus (PL) muscles, the Achilles tendon (AT), and the plantar fascia (PF). Stiffness (S) reflects the resistance of tissue to an external force that changes its shape and is reffered as N/m (Newton/metre). All measurements will be performed on both extremities. To ensure standardization, appropriate anatomical reference points for each structure will be marked prior to measurement

The MyotonPro device (Myoton AS, Estonia) will be used to evaluate the the damping coefficient (D) of gastrocnemius, tibialis anterior (TA), peroneus longus (PL) muscles, the Achilles tendon (AT), and the plantar fascia (PF). The damping coefficient (D) characterizes elasticity. All measurements will be performed on both extremities. To ensure standardization, appropriate anatomical reference points for each structure will be marked prior to measurement

The MyotonPro device (Myoton AS, Estonia) will be used to evaluate the Rr relaxation time of the gastrocnemius, tibialis anterior (TA), peroneus longus (PL) muscles, the Achilles tendon (AT), and the plantar fascia (PF). The relaxation time (R) of is reffered as mechanical stress and is shown as ms (milliseconds). All measurements will be performed on both extremities. To ensure standardization, appropriate anatomical reference points for each structure will be marked prior to measurement

The MyotonPro device (Myoton AS, Estonia) will be used to evaluate the creep (C) parameters of the gastrocnemius, tibialis anterior (TA), peroneus longus (PL) muscles, the Achilles tendon (AT), and the plantar fascia (PF). Creep (C) is defined by the ratio of relaxation time to deformation time. All measurements will be performed on both extremities. To ensure standardization, appropriate anatomical reference points for each structure will be marked prior to measurement

Lower extremity alignment will be assessed by calculating the Q angle. To evaluate the Q angle, participants will be asked to lie in the supine position with the knee joint in full extension. The Q angle will be measured using a goniometer as the angle formed between a line drawn from the anterior superior iliac spine (ASIS) to the midpoint of the patella and a line drawn from the midpoint of the patella to the tibial tuberosity, and the values will be recorded

It is a widely used test for evaluating foot biomechanics disorders and related musculoskeletal problems, used to assess foot arch structure and pronation level (38). The navicular height will be measured in a barefoot full weight-bearing position. The vertical distance between the navicular tuberosity and the ground will be assessed.

Hip flexion muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Functional mobility and dynamic balance will be assessed using the Timed Up and Go (TUG) test. It is a simple and reliable test that is frequently used in older adults to assess an individual's mobility, balance, walking ability, and risk of falling. The Time Up Go test is commonly used in individuals who have undergone total hip arthroplasty, and it has been shown to have high test-retest reliability and good construct validity in this population

Hip functional status will be assessed using the Hip Outcome Score. This questionnaire consists of four main parameters assessing pain, functional status in various activities (limping, use of support, walking distance, stair climbing, putting on/taking off socks, sitting, and using public transportation), absence of deformity, and range of motion. Each parameter includes items that evaluate the respective domain, and each response option is assigned a corresponding score. At the end of the questionnaire, these scores are summed to obtain a total score. The questionnaire is scored on a scale from 0 to 100, where 90-100 is classified as excellent, 80-89 as good, 70-79 as moderate, and scores below 70 as poor.

Ankle mobility will be measured using a fluid-filled inclinometer and the weight-bearing lunge test (knee-to-wall test). The knee-to-wall test is a valid and reliable test that assesses joint range of motion in the closed kinetic chain of the lower extremity and provides a passive measure of ankle dorsiflexion range of motion

Foot posture will be assessed using the Foot Posture Index in a relaxed standing position, based on six criteria related to the rearfoot and forefoot. Each criterion will be scored on a scale from -2 to +2. Negative values indicate supination, while positive values indicate pronation. Total score represents overall foot posture

The individuals' fear of movement or avoidance will be assessed using the Tampa Scale for Kinesiophobia (TSK). The TSK is a valid and reliable measure used to evaluate fear of physical activity and fear-avoidance beliefs related to movement. The scale is appropriate for use in individuals who have undergone total hip arthroplasty. This scale consists of 17 items rated on a 4-point Likert scale ranging from "strongly disagree" to "strongly agree." During scoring, items 4, 8, 12, and 16 are reverse scored, and a total score is then calculated. The total score ranges from 17 to 68. A score of 17 indicates no kinesiophobia, while a score of 68 indicates severe fear of movement. The cut-off value of the scale is 37; scores above 37 are considered to indicate high levels of kinesiophobia.

The validated Forgotten Joint Score Questionnaire (FJS-12) will be used to evaluate patients' return to daily life activities following treatment. The FJS-12 is a questionnaire consisting of 12 items that assesses joint awareness during activities of daily living using a 5-point Likert scale. For scoring, all responses are summed and divided by the total number of answered items. The resulting mean value is multiplied by 25 to transform the score to a 0-100 scale, and then subtracted from 100. Higher scores indicate the extent to which the patient is able to forget the operated side (%), reflecting better adaptation to activities of daily living.

The International Falls Efficacy Scale (FES-I) will be used to measure the participants' confidence in performing activities of daily living without fear of falling.The FES-I consists of 16 items that assess individuals' confidence in their ability to perform activities. Participants rate each item on a scale from 1 ("no concern at all") to 4 ("very concerned"), resulting in a total score ranging from 16 to 64. Higher scores indicate lower self-confidence in performing daily activities without falling

The SF-12 questionnaire will be used to assess participants' quality of life. In the literature, it has been used to measure the quality of life in patients who have undergone hip arthroplasty. The SF-12 consists of 12 items in total, covering questions related to two main domains: physical health and mental health. The questionnaire is scored using computer-based scoring algorithms, and higher scores indicate better health status. With this algorithm, physical health and mental health scores are calculated separately

It is a widely used test for evaluating foot biomechanics disorders and related musculoskeletal problems, used to assess foot arch structure and pronation level (38). The navicular height will be measured in a non-weight-bearing position. The vertical distance between the navicular tuberosity and the ground will be assessed.

It is a widely used test for evaluating foot biomechanics disorders and related musculoskeletal problems, used to assess foot arch structure and pronation level (38). Navicular drop will be calculated by subtracting the navicular height measured during weight-bearing from the navicular height measured during non-weight-bearing condition.

Hip extensor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Hip abductor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Hip a dductor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Knee flexor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Knee extensor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Ankle Dorsiflexor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Ankle plantar flexor muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Intrinsic foot muscle muscle strength will be assessed using a hand-held dynamometer (Lafayette Instrument, Lafayette, IN). The maximal isometric strength will be recorded as Newton (N)

Lower extremity function will be assessed using the Lower Extremity Function Score (LEFS). It consists of 20 questions related to activities of daily living. It is used by clinicians to assess patients' baseline, progressive, and final functional status. It allows evaluation of deteriorating functional capacity in patients. For each row, the degree of ability to perform the specified function is scored from 0 to 4 across columns (0 = extreme difficulty or inability to perform the activity, 4 = no difficulty at all). The maximum possible score is 80. In our study, the LEFS (%) was calculated as: (LEFS score / 80) × 100. A low score indicates severe functional limitation, whereas a high score indicates good functional status. The minimal clinically important difference for the scale score is 9.