Objective: the effect of trigger point release of patients with tension type headache on reduction of pain and grip force and grip endurance. Inclusion criteria: trigger points, nausea, vomiting and photophobia during attacks. Exclusion criteria: anti-anxiety and anti-depression drugs, upper extremity and spinal injuries during the past year, paresthesia and neurological symptoms. population and sample size: 28 patients with tension type headache(men and women). Interventions: Treatment phase starts in 6 sessions in 2 weeks. In each session one hot pack used for neck muscles for 10 min afterwards, post isometric relaxation technique used for muscles with trigger points. this technique is associated with eye movements and breathing pattern. During contraction, breathe out and look for the contraction and at rest, exhale done and look for opposite side. Contraction repeat 5-3 for each session 10 seconds. Measurement: measured grip strength and endurance before and after interventions using dynamometer. measured pain before and after interventions using Visual Analog Scale