Iontophoresis therapy (MgO4 will be applied to the active positive electrode and the treatment will be repeated twice a week for four weeks) + conventional therapy (Splint + Stretch + strength).

conventional therapy (Splint + Stretch + strength) twice a week for six weeks

Iontophoresis therapy (MgO4 will be applied to the active positive electrode and the treatment will be repeated twice a week for four weeks) + conventional therapy (Splint + Stretch + strength).

. Visual analogue scale will be used to assess the pain intensity level. Pain intensity Level will be measured using the VAS that consists of a 10-cm straight line with endpoints defining pain intensity.All patients will be asked to mark their pain level that corresponds to their pain intensity on the line between "0", representing "no pain", and "10", representing "the worst pain imaginable". The distance between "0" and the mark made by the patients was measured. Difference in pain intensity will be recorded at rest, at night, and during activity (repeated elbow movement) at baseline and after treatment

Cyriax Resisted Muscle Test: In this test, the patients will be seated and positioned with their upper extremities relaxed. The test will include elbow extension, third finger extension, pronation, and supination. All tests were conducted in a standardized manner using maximal isometric resistance and allowing no movement at either joint. Based on manual muscle testing principles, the examiner will hold the contraction for approximately 3 s to allow the patients time to build to maximum tension. The examiner will stabilize the patients' elbows with one hand and applied resistance with other hand. The patients will be instructed to report the onset of or an increase in pain. The results of the resisted tests will be recorded as "strong and painless", "strong and painful", "weak and painful", and "weak and painless". The Cyriax Resisted Muscle Test was conducted at baseline and after treatment

Maximum grip strength: by using hand dynamometer the patients will be seated on an armless chair with 90° flexion of hip and knee, their shoulders with 0° abduction and in the neutral position, their elbow at 90° flexion and their forearm in the neutral position, and their wrist in semi pronation with an upright thumb to provide a stronger grip. The protocol will consist of three maximal isometric contractions without pain for 5 s with a rest period of at least 60 s. The patients will perform three trials of grip strength using their involved and non-involved hands while maintaining 90° elbow flexion and neutral forearm position. The patients followed a verbal command of "slowly push, push, push, push, and relax" for each isometric contraction to ensure that the contractions lasted for approximately 5 s. The patients will be also asked to squeeze the dynamometer as hard as possible without the sensation of pain. The mean strength of three measurements will be recorded in kilograms

Joint range of motion evaluation: With the wrist in neutral position, the angle achieved during maximum wrist extension was assessed using the Clinometer (Plaincode Software Solution, Stephanskirchen, Germany) which is a smartphone application.

The forearm placed on the chair armrest, with 90 degrees of elbow flexion, the angle between the radius and the second metacarpal was measured by the radial styloid axis of the forearm in pronation. The interrater reliability for angular measurements was 0.76-0.95 (Lim and Shin, 2016).