Muscles - strength
We often associate strength with Arnold Schwarzenegger, Bruce Lee, weight lifters, tradies, and others who have to lift heavy things all day. But strength is in everyone! Muscular strength is important to us everyday. Without strength, we would not be able to move, we would not be able to resist forces that are imparted on us throughout the day, and we would be at greater risk for injury and pain! In this blog we’ll talk about what strength is, how we can build strength, why a lack of strength can cause pain, and how physiotherapy can help.
Picture showing various old and young people of different genders displaying the many different types of muscle strength.
What is strength?
“Muscular strength is the ability of a muscle to exert a maximal external force.”
American College of Sports Medicine, 2013
Strength is the ability to generate force. Whether the force we are resisting are weights in the gym, tools on the job, or just to help us stand against gravity, the muscles are all working hard to generate force to help us move the way we want to.
Weakness, which is the inability to generate force, can be caused by a multitude of factors. Weakness can be caused by:
Small muscles without enough muscle fibres
Impaired nerve signalling (firing signal from brain not transmitted well)
Muscle fatigue (muscle has been working hard and is now tired)
Lack of energy (energy that fuels muscle is depleted)
Injury (muscle is damaged)
How can we build strength?
To get stronger, we must train our muscles and body. But how do we do this, while preventing injury from overloading too much? We must gradually increase the weight of the things we are lifting, to allow the muscle to get grow and get used to the increasing weight! This is called Progressive Overload - gradually increasing the demands on your muscles to generate force.
Picture showing 'progressive overload', a person climbing up the ladder of improvement
To optimally work our muscles and prevent injury, and rather than lift a super heavy weight once and risk injury, or lifting a light weight a hundred times, we should aim to lift a weight for a certain amount of repetitions and sets. The American College of Sports Medicine, one of the leading bodies of exercise science, recommends:
Intensity: 60-70% (difficulty/intensity of effort)
Volume: 1-3 sets of 8-12 repetitions
Rest period: 1-2 minutes between sets
To prevent overtraining, large increases in weight or repetitions should be avoided. A gradual increase of 2-10% of load can be applied when you are able to do 2 repetitions over the desired number of repetitions on the last set of the exercise. This is known as the “Rule of two”, add weight when you can do two more than you were aiming for!
Training specificity - focusing on what to train
Our bodies will get strong depending on what we train it in. For example, if we want strong biceps, we would have to do many bicep curls. If we want to be strong at lifting boxes, we train by gradually lifting heavier boxes.
However there are several exercises that recruit a large amount of muscles in our body that we can use to build overall strength in all major muscle groups. These exercises are called compound exercises because you use more than one muscle group at a time.
Picture showing people doing 'the big three' - squats, bench press and deadlift
These three exercises are excellent for building full body strength. The squat is builds overall lower body, and back strength - helping improve your ability to climb stairs, walk up hills, and get up from a seated position. The bench press builds overall upper body strength - helping improve your ability to push a shopping trolley and open heavy doors. The deadlift builds overall back strength and leg strength - helping improve your ability to lift heavy objects off the ground, and other pulling actions.
Lack of strength - a possible cause of pain?
Sometimes the reason why we have pain could be because we are weak in certain areas. If some muscles are weaker than others, that could create an imbalance in the force that the muscles put our body through. For example, if one side of the body is much much weaker than the other, the way we walk may not be properly “aligned” and put different joints under too much load in an irritated position. Joints generally like being worked in certain positions. Imbalances might pull them into angles where they might become irritated.
How can physiotherapy help?
If you think your pain might be caused by a lack of strength, weakness, or muscle imbalance, physiotherapy might be for you. A physiotherapist can assess your movement and give you a better understanding of your muscle strength and movement patterns. A physiotherapy session might consist of:
movement assessment and screening, to determine if the way you move is contributing to your pain
muscular strength test, to determine if certain muscles are weak, or if you have a muscular imbalance
therapeutic exercise program, to strengthen key muscles that will address previously identified deficits
symptom management (massage, heat, cupping, acupuncture), to help relieve pain in the short term, and help you feel better during exercise.
If you have any further questions on muscle weakness and how you might be able to improve your muscle strength and movement quality, please give us a call at 3061 7128 and talk to one of our physiotherapists.
Blog and videos by UQ Physiotherapy student undertaking clinical placement, supervised by principal physiotherapist, Winnie Lu.
Baechle, T. and Earle, R.; Essentials of Strength Training and Conditioning