Why do so many females resort to the ever popular abductor/adductor machines that we see in today's commercial gyms? Commonly known as the "inner and outer" machines by women, these machines are dinosaurs and have resulted in thousands of hours wasted away by users (men included). Everyday, females sit on these machines and perform a standard set of 15 reps or sometimes a "high rep" set of 20-30; and then rest by sitting there and wasting away. Waiting for what?
The position that the abductor/adductor machine places the body in plays no role in human movement function. The machine is designed to isolate (not integrate) the adductors and abductors for strength and hypertrophy. Whats wrong with that? Nothing if you are a female physique competitor and need more "outer sweep" to your thighs, or need to bring your adductors up to par with your quads. The machines are more detrimental than good for the average gym goer.
Isolation is good for hypertrophy, but it's not good for function. Especially for the adductors. Overly tight adductor muscles have a tendency to affect pelvic rotation, which can effect lower back health. The abductors (outer) when placed in the machines--usually in a knee flexed position--can stress the ilio-tibial band (IT) in someone with already tight IT bands. Most general population gym goers are desk-sitters and prone to IT band syndrome which can lead to knee tracking problems, knee pain, and low back pain. Because these muscles are attached to the pelvis, they work in conjunction with other muscles to "operate" the pelvis. The pelvis is the site of many central muscular attachments. It's a central unit for core muscles and very important for locomotion (running, walking). If certain muscles are strengthened without properly balancing the surrounding antagonists; most likely there will be an alteration in the hip joint and sacro-iliac joint; followed by the knee and ankle. Likewise, the entire kinetic chain can be interrupted.
In my experience, I have found that most men are tight in the adductors. Most women are weak in the adductors. So, what can we do to incorporate a strength component with an active stretch? I like a lunge movement. It can be implemented in different forms: lateral lunge, split squat, lunge reach, transverse lunge or reverse lunge. I teach the lunge to every client I encounter simply because there is an abundance of benefit to this movement to ignore it totally.
However, I am not oblivious that the lunge is also a tough exercise for most people that complain of some sort of knee pain. With that being said, I began using the "Kneel to Stand" drill as part assessment and part progressive movement preparation. The drill calls for someone to kneel down on a thick mat or Airex pad. Using one side, the person must bring flex the hip and bring one knee to the front. This portion will tell you alot about hip flexor strength (primarily psoas function) and hip stability. If someone has poor hip stability (coupled with weak core), they will lose balance immediately. If they have weak adductors, the knee will cave-in immediately as they rise from the genuflect position. If they have SI joint pain, they will grimace or complain of low back pain with the hip flexed position and accelerating upwards. If they have overly tight hip flexors, they will comment on the "stretch" they feel in the opposite thigh.
You see, so many things occur in one movement when you involve the pelvis. Now, back to the adductors. I like the side lunge for adductor work simply because it incorporates other muscle groups into the equation and adds a plus in the function column of your exercise program. You can find an abundance of drills like the Kneel to Stand--designed to facilitate a great looking lunge in my DVD: