The human body is a complex machine, with each muscle playing a key role in our overall physical health and performance. One such muscle, the posterior deltoid, has a crucial role in our ability to move our arms and maintain good posture. This article provides a comprehensive overview of the posterior deltoid, its anatomy, its functions, and how to effectively train it.
The posterior deltoid, often referred to as the "back shoulder," is part of the deltoid complex, a group of three muscle bundles. This muscle bundle originates from the spine of the scapula, hence the alternate name "spinal," and attaches to the deltoid tuberosity of the humerus along with the other two bundles.
The primary role of the posterior deltoid is to facilitate specific humerus movements. More specifically, it extends, extra rotates, and abducts the shoulder in the transverse plane. It's noteworthy that most of the posterior deltoid's functions are antagonistic to those of the anterior deltoid, meaning they perform opposite movements.
Like all muscles, the posterior deltoid responds to training. Resistance training, which involves working against resistance, is particularly effective for conditioning this muscle. This can be achieved through calisthenics, training with overloads or elastic bands, or a combination of these methods.
To specifically target the posterior deltoid, training with free weights and isotonic machines is recommended. The primary goals should be to improve strength and resistant strength, both of which contribute to an increase in the myofibrillar and sarcoplasmic mass of the contractile tissue, leading to muscle hypertrophy.
When training the posterior deltoid, it's important to consider the density of oxidative motor units, often referred to as red fibers. Some suggest that due to this density, the shoulders should be trained mainly at high repetitions. While this isn't entirely accurate, it does lead us down the right path.
To increase strength and myofibrillar mass, muscles need to be trained with high levels of muscular tension, which typically means low repetitions. However, the isolation movement of the posterior deltoid doesn't lend itself to the use of high overloads. This is best achieved with multi-joint pulling movements, which can be adjusted to give more emphasis to the shoulders.
To stimulate the growth of all cytoplasmic components, training should involve the exhaustion of phosphagen reserves, the breakdown of glycogen, and the production of lactic acid. This requires more repetitions until you approach muscle failure. There are numerous exercises designed specifically for this purpose, which we will explore further in the next section.
Exercises for the posterior deltoid can be divided into two main categories: multi-joint exercises and single-joint isolation exercises.
In addition to weighted exercises, bodyweight training plays a crucial role in posterior deltoid development. Exercises such as pull-ups, muscle-ups, and front levers engage the posterior deltoids significantly, offering a functional approach to muscle strengthening and conditioning.
In conclusion, understanding the anatomy and functions of the posterior deltoid is crucial for effective training. With the right exercises and training techniques, you can strengthen and condition this important muscle, improving your overall physical health and performance. Remember, it's always advisable to seek professional guidance when starting a new training regime to ensure you're performing exercises correctly and safely.