There are many benefits to forward bends, both standing and sitting.
The forward bend asanas or postures have a massaging action on the organs in the upper body. Forward bends open up your back, promote total exhalation of air from the lungs by compressing the chest and also help to calm down your mind. The forward bending asanas or postures bend the back to the shape it was when the body was in the womb (called the primary curve). This makes some space between the spinal vertebrae improving circulation around it. The nerves from all the different organs in the body pass through the spinal cord. Creating length and space in the spine counteracts compression and bending forward to look inward can promote introspection.
The forward bend poses give an internal massage as well as they improve the circulation to the various organs like the abdomen, pancreas, liver, intestines and kidneys. They also help to lengthen and strengthen the hamstrings, the inner leg muscles, make the back muscles more supple and boost leg and knee strength. Forward bend poses help balance the air in the body. This has beneficial effects on digestion, body temperature, menstruation, childbirth, etc.
Yet forward bends can also be a challenge to many people, especially those with tight hamstrings. Common physical conditions, such as overstretched back muscles and rounded shoulders (most likely from sitting in front of a computer for hours) can be improved with forward bending poses. Yoga can help us dissolve patterns helping us to discover new ease in our forward bends.
Forward bends are not about how deep you can go but rather how deeply you can release. There’s no need to struggle, or force the body to get into a position it's not ready for. Instead, surrender to the present moment, notice the experience, and settle into the breath.