Final answer:
An anterior pelvic tilt results in tight iliopsoas and quadriceps muscles, with lengthened hamstrings and abdominal muscles. It's vital to target the lengthened muscles with strengthening exercises and the tight ones with stretching to promote better posture.
Step-by-step explanation:
When the pelvis is tilted downward and forward in an anterior tilt, certain muscles become tight while others are lengthened. Tight muscles in this condition typically include the iliopsoas group (which is made up of the psoas major and iliacus), as well as the quadriceps, and sometimes the erector spinae, due to their position and action in anteriorly tilting the pelvis.
The lengthened muscles in an anterior tilt are usually the hamstrings, gluteal muscles (including gluteus maximus, medius, and minimus), and abdominal muscles, specifically the external and internal obliques, transversus abdominis, and rectus abdominis. This lengthening is due to the pelvic tilt positioning these muscles in a stretched state.
To maintain a healthy posture and prevent muscle imbalances, it is important for one to engage in activities that strengthen the elongated muscles and stretch the tightened ones, thereby promoting a more neutral pelvic position.