Their number: 300; female and male students, will earn 39 points or less of Smartphone Addiction Proneness Scale. Pain Pressure Threshold and Hand Grip Force will Measured for them.

Their number: 300; female and male students, will earn 40 points or more of Smartphone Addiction Proneness Scale. Pain Pressure Threshold and Hand Grip Force will Measured for them.

The pain pressure thresholds (PPTs) will be measured using an pressure algometer commander over potential trigger points (TrPs) on the body for upper fiber of trapezius, and sternocleidomastoid muscle.

Using Algometer to measure pain pressure for upper trapezius trigger point which lies in the more horizontal fibers of the upper trapezius on the back of the shoulder, about halfway between spine and the acromion on right and left side for 3 repetition for each

Using Algometer to measure pain pressure for sternocleidomastoid muscle on right and left side for 3 repetition for each. Measurement will includes three sites on each side:

1. upper part of the sternal division of the muscle near to its insertion into the mastoid process. 2. he mid-part of the sternal division of the muscle. 3. lower end of this division near to its attachment to the sternum.

For measuring the grip strength, the subjects will be asked to sit on a chair with their hip joint flexed at 90 degree, and shoulder joint in a neutral position.

The elbow is fixed at 90 degree flexion, forearm in a neutral position, and wrist at 0 to 15 degree radial deviation.The test will be performed twice, and the higher value between the two measurements will be selected.

The subjects are allowed a rest time of more than 5 minutes after the first measurement to avoid examiner bias and to decrease physical stress