Range of Motion in Exercise: Why it Matters
You may have heard coaches emphasize using “full range of motion” before performing specific movements, but what does this really mean? How does it differ from partial range of motion, and why would one choose full range over partial? Understanding these concepts is crucial for anyone aiming to optimize their workouts, whether for strength, muscle growth, or athletic performance.
What is Range of Motion?
Range of motion (ROM) is the extent to which a joint can move in a particular direction, often measured in degrees. Each joint in the body has a unique range, allowing different degrees of movement based on structure and flexibility. For example, in a bicep curl, the elbow joint typically moves from around 0 degrees (fully extended) to about 130 degrees (fully flexed) through the movement. Similarly, when squatting, the knee joint may go from 0 degrees at a standing position to as much as 140 degrees of flexion, depending on one’s flexibility and training goals.
Full vs. Partial Range of Motion
Full Range of Motion (ROM): Performing a movement through the entire extent that a joint can naturally achieve, often activating multiple muscles more deeply. A full squat, for instance, would involve lowering until your hips go below your knees, enhancing the stretch and activation in your glutes and hamstrings.
Partial Range of Motion (ROM): Executing a movement over a portion of the joint’s possible range, such as performing a bicep curl to 90 degrees rather than going below parallel. Partial ROM can be beneficial for isolating specific muscles, which can be useful in certain training contexts.
What Do The Studies Say About This?
When training in the gym, the main goal is to stimulate adaptations in the body, such as increases in strength, muscle size, power, or endurance. Studies comparing full and partial range of motion (ROM) have shown that how we move through exercises can significantly impact these adaptations. Generally, research suggests that training with a full ROM results in similar or even superior gains in muscle size compared to training with a partial ROM.
In terms of muscle hypertrophy, specifically in the lower body, four key studies have examined the effects of ROM variations. The findings are consistent: a full ROM yields comparable or better results in terms of muscle growth when compared to partial ROM. This outcome likely occurs because full ROM exercises recruit more muscle fibers, engaging the muscles through the entire length of contraction, which promotes greater development. However, when it comes to the upper body, the research is less conclusive. Studies are limited and show mixed results, suggesting that individual factors, such as training goals and experience, may play a larger role in the decision to use full or partial ROM.
The Exceptions
While a full range of motion is often optimal for building muscle size and strength, there are specific cases where a partial ROM might be more appropriate:
Sport-Specific Training: For athletes, certain sports may demand strength or power in limited ranges of motion. For example, a cyclist might train with partial squats to develop power in a range that mimics their pedaling motion. By focusing on this smaller range, athletes can train their bodies to generate power precisely where they need it for their sport.
Injury and Mobility Limitations: Injuries or mobility issues can restrict a person's ability to perform exercises in a full range. For example, someone recovering from a knee injury might struggle to perform deep squats. In such cases, using a partial ROM allows for a safer, more manageable approach while still benefiting from resistance training. Additionally, those with limited joint flexibility or stability may find partial ROM beneficial as they work to gradually increase their mobility.
Progressive Overload and Muscle Activation: In certain advanced training strategies, athletes use partial ROM to increase load in a specific range where they are strongest. This technique, known as "partial reps," is often applied in exercises like bench presses or squats, where lifting a heavier weight for a shorter range can help develop joint stability and gradually prepare the body for lifting heavier weights over time.
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