Nothing messes with one's progress in the squat faster than a muscular imbalance, particularly when it concerns the legs. Just as how we tend to favour one arm over the other, it is exceedingly common for the dominant leg to possess more strength. Even in bilateral exercises such as the squat, there is the subconscious tendency to rely more on the stronger musculature in one side of the body to overcome heavy loads. Correcting this won't just make you stronger as a whole, but will also lead to more resilience against injuries.
Unilateral leg exercises are plentiful enough: loaded/unloaded split squats and bulgarian split squats, skater squats and step-ups are just some of the more common ones. One feature that all have of them share is the use of implements such as dumbbells and kettlebells when it comes to loading. While this makes for simple exercises than can be performed in just about any gym setting, it also denotes a shared weakness: limitations in loading.
Dumbbells and kettlebells are useful, but they require more effort when it comes to stabilisation. Coupled with how cumbersome they tend to get as the load goes up and the grip strength required to handle them, the ceiling for loading isn't as high as one would get with a barbell. Yet doing unilateral exercises with a loaded barbell on the back may be too daunting for some, given the risk of going off-balance. Employing a trap bar makes for a happy compromise between the two without sacrificing any efficiency.
Location and equipment courtesy of TripleFit
The dual-handled design of the trap bar makes it much easier to control, and the sleeves allows for the same amount of loading you'd expect with a barbell. Upon standing up with the trap bar, simply put one leg forward and the other backwards by about one step. Squatting is then a simply matter of lowering the hips and bending the knee, before coming back up. Stopping your rear knee just short of touching the ground (or lightly touching it) allows you to place more tension on the legs, and also saves you from incurring any nasty bruises from crashing down on your knee.
Not only is the trap bar split squat a great way to elevate the loading potential of your unilateral lower body training routines, but it's also a great way for lifters experiencing pain or recovering from injuries to continue training in a safe yet productive manner. The position of the trap bar's load relative to the body's midline creates very little sheer stress on the lower back, and the unilateral nature of the movement forces a reduction of load – handy for inflamed joints. Tempo training also works great with trap bar split squats, and is almost guaranteed to leave you sore!
Unilateral training can and should be done with heavy loads every now and then. While utilising more moderate loads with higher repetitions can be useful in terms of generating metabolic stress and muscular damage, the higher mechanical tension afforded by heavy loads can be the ticket to increased hypertrophy, especially if the lifter has been on the aforementioned style of training for quite some time. If your squat has been stagnating recently, maybe it's time you give your legs the attention it needs to catch up!