By Mandie Martuzzo, PT
Board-Certified Clinical Specialist Orthopedic Physical Therapy
During the stay-at-home period, we have all been much less active than we are used to. Even if we have made an effort to exercise, we are still engaging in much less daily activity than normal. Going to work, walking around, running errands, all add physical activity to our days.
Tissue responds to stress placed on it. So, less stress on the tissue (e.g. inactivity) can lead to muscle atrophy or decreased strength in muscles and tendons and decreased bone density. Decreased physical activity can also reduce the motor recruitment of muscle fibers, meaning it takes more effort to turn the muscle on than it did before.
Alternately, physical activity and exercise will increase circulation around muscle fibers, allowing more oxygen and greater muscle performance during endurance training. Resistance exercise increases muscle fibers (e.g. muscle mass and strength). Tendons also become stronger to prevent tendon damage, as the force produced by muscles is transferred to tendons that attach the muscle to bone.
Keeping in mind the importance of loading on muscle and tendons and the effects that it can have, it is important that we cautiously return to our normal activity and exercise so we can avoid strain and sprain injuries.
If done improperly, resistance training can lead to overuse injuries of the muscle, tendon, or bone. These injuries can occur if the load is too heavy or if the muscles are not given sufficient time between workouts to recover or if joints are not aligned properly during the exercises. It is also common for an injury to occur when there is a sudden increase in duration, intensity, or frequency of an activity. (American Academy of Orthopedic Surgeons. Available from: orthoinfo.aaos.org. Accessed 26 February 2019).
A muscle strain occurs when muscle fibers cannot cope with the demands placed on them by exercise overload and leads to tearing of the fibers. It is a contraction-induced injury in which muscle fibers tear due to extensive mechanical stress. This mostly occurs as result of a powerful eccentric contraction or over stretching of the muscle. Therefore, muscle strains typically occur during non-contact sports with dynamic characteristics, such as sprinting and jumping. (Garrett WE. Muscle strain injuries. Am J Sports Med. 1996; 24:S2-88)
Some considerations or things to keep in mind as you increase your activity levels to prevent injury include:
* Heart rate variability and fitness level: Training too hard/too fast can lead to muscle injury. Monitor your heart rate and how quickly your heart rate lowers from 125 bpm after intense exercise. How fast your resting heart rate climbs and then lowers after activity is a good indication of your current cardiovascular performance. Then you can ensure that you are working out at an intensity level that is within a moderate range.
* Eccentric strengthening: This type of exercise trains your muscles to maintain strength and tension while they are lengthening. This helps prevent tears, which often occur when a muscle suddenly elongates and must absorb a high amount of force.
* Vitamin-D can impact muscle strength/performance, and deficiency can cause premature muscle fatigue leading to injury. If you think you may have low Vitamin-D levels, check with your doctor and get recommendations for a supplement if needed. (https://www.hindawi.com/journals/bmri/2015/953241/)
* Warm up before and stretch after: A short period of warm up activity prior to exercise will help to prevent an injury. Save the stretching for after exercise to help reduce chemical build-up in the muscles and reduce soreness.
* Consider a Wellness360 exam with a physical therapist. PhysioPartners offers the Wellness360 Annual Exam for an evaluation of strength, mobility, and function that can help find areas where you can improve to avoid injury.
Your physical therapist is here to keep you moving and return to your life with confidence!