The study will be randomised clinical trial. This study will be conducted at the University of Lahore Teaching Hospital, Lahore, Pakistan. A sample size of 48 will be randomly allocated into two experimental groups, (24 participants in each group), by using sealed envelope method. All the screened and willing participants were randomly allocated into two groups. Group A will be given navicular mobilization and group B will be given conventional therapy with navicular mobilization. Treatment will be given for 4 weeks 4 sessions/ week with total of 16 sessions. Assessment to be taken at baseline, 2nd week and 4th week. The participants randomly allocated in Group A will receive navicular mobilization. In navicular mobilization, Subject- prone lying, Therapist- standing on tested side. In the prone position, when the foot is stabilized by a towel underneath, navicular mobilization is administered. The therapist's fixing hand wraps the calcaneus, grasps the talus bone, and fixes it. By placing the thumb on the plantar surface of the foot and pushing with the thumb of the other hand in a dorsal direction, navicular mobilization is provided. This dorsal glide will be given with 2 sets of 5 minutes. Each session will be of 30 minutes. Four sessions will be given per week for 4 weeks. The participants randomly allocated in Group B will receive conventional physical therapy with navicular mobilization. In navicular mobilization, Subject- prone lying, Therapist- standing on tested side. In the prone position, when the foot is stabilized by a towel underneath, navicular mobilization is administered. The therapist's fixing hand wraps the calcaneus, grasps the talus bone, and fixes it. By placing the thumb on the plantar surface of the foot and pushing with the thumb of the other hand in a dorsal direction, navicular mobilization is provided. This dorsal glide will be given with 2 sets of 5 minutes. In Conventional therapy, ultrasound with an output of 1.5 w/cm2 for 7 minutes using a continuous mode with a frequency of 3MHz, stretching of planter fascia, strengthening of medial arch and foot surround muscles such as calf and tibialis posterior will be done by doing exercises like arch lift, heel raise, towel pickup, toe lift, strengthening exercises for intrinsic foot muscles, standing toe curls, towel toe curls and Ice pack for 10 minutes .These exercises will be performed in a set of 3 with 12 repetitions in each set in one session. This treatment session will be of 30 minutes and will be give 4 session per week for 4 weeks.

• Screening: Participants who meet the inclusion criteria will be recruited using a convenient sampling technique. This involves selecting participants who are readily available and willing to participate in the study.

• Allocation: Eligible participants will be screened and informed about the study including its purpose, procedures, potential risks and benefits. Informed consent will be obtained from each participant prior to their formal enrolment in the study.

• Randomization: Following the baseline assessment, the randomization was conducted using the Online Randomizer tool (https://www.randomizer.org/). By specifying the group numbers, participants per group, and the total participants, unique identification numbers were generated for each participant.

• Blindness: This study a single blinded, the patients were kept blinded about the study.

• Intervention Group A: The participants randomly allocated in Group A will receive navicular mobilization. In navicular mobilization, Subject- prone lying, Therapist- standing on tested side. In the prone position, when the foot is stabilized by a towel underneath, navicular mobilization is administered. The therapist's fixing hand wraps the calcaneus, grasps the talus bone, and fixes it. By placing the thumb on the plantar surface of the foot and pushing with the thumb of the other hand in a dorsal direction, navicular mobilization is provided. This dorsal glide will be given with 2 sets of 5 minutes. Each session will be of 30 minutes. Four sessions will be given per week for 4 weeks.

Group B: The participants randomly allocated in Group B will receive conventional physical therapy with navicular mobilization. In navicular mobilization, Subject- prone lying, Therapist- standing on tested side. In the prone position, when the foot is stabilized by a towel underneath, navicular mobilization is administered. The therapist's fixing hand wraps the calcaneus, grasps the talus bone, and fixes it. By placing the thumb on the plantar surface of the foot and pushing with the thumb of the other hand in a dorsal direction, navicular mobilization is provided. This dorsal glide will be given with 2 sets of 5 minutes. In Conventional therapy, ultrasound with an output of 1.5 w/cm2 for 7 minutes using a continuous mode with a frequency of 3MHz, stretching of planter fascia, strengthening of medial arch and foot surround muscles such as calf and tibialis posterior will be done by doing exercises like arch lift, heel raise, towel pickup, toe lift, strengthening exercises for intrinsic foot muscles, standing toe curls, towel toe curls and Ice pack for 10 minutes .These exercises will be performed in a set of 3 with 12 repetitions in each set in one session. This treatment session will be of 30 minutes and will be give 4 session per week for 4 weeks.

Outcome Variables:

1. Pain (Numeric Pain Rating Scale)
2. Disability (Foot Function Index)
3. Navicular height drop (Navicular drop test)

Inclusion Criteria:

• Participants between 18 to 32 years of age.
• Plantar fasciitis with flat foot.
• Positive Flat foot cases diagnosed with foot print measurement
• Both males and females
• Unilateral or bilateral involvement with chronic plantar fasciitis
• Diagnosed case of plantar fasciitis will be taken with navicular drop
• Navicular Drop (ND) of > 10mm

Exclusion Criteria:

• Patients with Peripheral vascular diseases
• Patients with History of fractures in the lower limb
• Patients with Skin infections and wounds on the foot
• Patients with any neurological deficit involving foot
• Patients with a history of foot or ankle surgery.

Study will be single and assessor blinded. Participants will be masked about other groups but they will know what treatment they will be receiving or what exercises they will be doing. Principal investigator would also not be masked or blinded because investigator would be applying the techniques on participants of both group. So participant and and principal investigator cannot be blinded. Only assessor will be blinded and he will take outcome measures without knowing the problem and treatment techniques.