The purpose of this study will be to investigate:

1. Relationship between forward head posture and hamstring tightness in young adults
2. The gender specific effect (female versus male) on the relationship between forward head posture and hamstring tightness in young adults

Forward head posture imposes approximately 3.6 times more pressure on the neck than proper posture, and the prolonged burden of supporting the increased head weight can potentially cause neck pain, fatigue, and chronic musculoskeletal disorders. Hamstring tightness can cause posterior pelvic tilt, which leads to decreased lordosis of lumbar spine and resulting in LBP. Hamstring tightness can contribute to various issues, including muscle strains,loss of lumbar spine curvature, sacroiliac joint disorders, and plantar fasciitis. These problems primarily arise due to misalignment of the body and imbalanced force distribution between muscles and joints. Hamstring and sub-occipital muscles are connected by a neural system and sub-occipital muscles pass through the dura mater. this is called superficial back line (SBL), which connects the lower extremities, trunk, neck, and head protects the body's entire posterior surface and provides an important function of up-righting the body. There is still lack of research work about the relationship between FHP and hamstring muscle tightness and the gender-specific effect (female versus male) on the relationship between FHP and hamstring tightness in young adults.

Inclusion Criteria:

• Both genders were included, with an age ranged between 18 and 25 years old.
• Participants with a CVA equal to or less than 49° were included (Haytham M. Elhafez, 2023).
• Body mass index was between 18 and 25 kg. /m2 (Haytham M. Elhafez, 2023).

Exclusion Criteria:

• Systemic disease
• History of hamstring injury within the last 2 years
• Previous knee injury
• Fracture in the spine or lower limb
• Spinal or lower limb surgery
• Pregnancy
• Congenital deformity
• Leg length discrepancy more than 2cm
• Acute spasm of hamstring muscles
• Neuromuscular disorders of the lower extremity, like stroke, muscular dystrophy and peripheral neuropathy
• History of any malignancy or infectious disease
• Spinal or limb deformities

males and females

young adults with forward head posture