Dealing with Injury
stop an exercise that causes the joint or muscle unusual pain.
Administer first aid. Allow time
for the joint or muscle to heal as you continue to workout using
exercises that do not further aggravate the injury during its
recovery. After sufficient recovery time, start back very conservatively
with a single set or brief bout with very light resistance. Continue
to slowly progress steadily, increasing the load or volume throughout
the following weeks, only if you can perform the load pain free.
Be cautious not to aggravate the injury by attempting to progress
too rapidly. Be aware that it is possible to not feel pain or
discomfort after over doing it until after the workout or the
next day - after it is too late. See a physician for serious
injuries or if the pain persists or gets worse. A sports medicine
physician specializes in exercise and athletic related injuries.
A physical therapist should also be able to refer you to a physician
knowledgeable in exercise related injuries for proper diagnosis.
A specialist can help you determine possible underlying causes
of the injury and make necessary program modifications to prevent
future injuries. See Adaptation
Criteria and Causes
- Range of motion (ROM)
- Return to activity
Bomgardner, Rich (Dec 2001) Rehabilitation phases and program
design for the injured athlete. Strength and Conditioning Journal
, Vol 23, Num 6, pgs 24-25.
Irritablility can be rated Low, Medium, or High based on 3
- Pain level (Score of 1-10)
- What it takes to provoke the symptoms
- Latency or time it takes the symptoms to resolve after provocation
Care must be taken when assessing patients of high irritability
because once symptoms are provoked, the remaining assessments
Tovin BJ (2006). Prevention and Treatment of Swimmer's
Shoulder. North American Journal of Sports Physical Therapy,
Strength Imbalance and Injury Relationship
Individuals with strength differences of more than 10% between
the quadriceps of the right and left legs were more likely to
sustain lower limb injuries compared to individuals without such
strength imbalances (Bender et al, 1964).
If these strength differences were due to past injury, one
could speculate that previous injury at least partly attributed
to increased the risk of injury, not necessarily the strength
imbalance itself, since past injury is most predictive of future
injury (see studies below) and past injury typically results
in weakness (and decreased range of motion) in the injured limb.
Ankle Sprain Predictors
BMI and past ankle sprains were much more predictive of future
injury in high school athletes than were balance, height, ligamentous
laxity, ankle tape/bracing usage, and hip strength balance. High
school football players were 16 times more likely to sustain
an ankle sprain if the athlete was overweight or obese and had
a history of ankle sprain. Incidentally, the use of preventive
taping or bracing did not reduce the incidence of injury.
Mirabella MR, Tyler TF & McHugh MP (2004) Risk Factors
for Ankle Sprains in High School Football Players. Journal of
Athletic Training. Supplement 39(2), 38.
Tyler TF, McHugh MP & Tetro (2004) Risk Factors for
Ankle Sprains in High School Athletes. Journal of Athletic Training.
Supplement 39(2), 37.
Strength losses from a particular movement following an injury
appear to also negatively affect strength of agonist muscle group.
For example, after initial recovery of left knee injury, left
quadriceps still remain deconditioned. Right leg regains strength
relatively quickly, but left leg may lag in strength as measured
by unilateral Leg Extensions or Single-leg Leg press. Consequently,
less force can be applied on left leg during Squats, Leg Presses,
and other similar movements. Interestingly, left hamstring (quadriceps
agonist and knee
stabilizer) can also remain weak, although it was not directly
impaired by knee injury. Also see Interdependent
Strength in strength training.
Exercise & Arthritis
Exercise can decrease pain and improve functional capacity,
ROM, and muscular strength
Felson DT, Lawrence RC, Hochberg MC, McAlindon T, Dieppe
PA, Minor MA, Osteoarthritis: New insights. Part 2. Treatment
approaches. Ann Intern Med. 133:726-737, 2000.
Casper JM, Berg K. Effects of exercise on osteoarthritis:
A review. J Strength Cond Res. 12:120-125, 1998.
The human foot has 26 bones, approximately 20 muscles, 33
joints, and over 100 ligaments holding it all together.
Connective Tissue Sheaths
Weight training may strengthen the sheaths of connective tissue
within and around the muscle by increasing their collagen content.
These connective tissues sheaths provide the framework that supports
muscle overload and are the main component in the tensile strength
and passive viscoclastic properties of muscle.
- endomysium surrounds individual fibers
- perimysium encloses groups of muscle fibers
- epimysium surrounds the entire muscle
Tensile strength and elasticity of bones decrease about 2%
per decade from age 20 to 90 years (Hayes, 1986).
Bone is only one fifth the weight of steel but can withstand
two times the compression force as granite, or four times the
compression force as concrete.
Weight bearing activities such as walking can prevent bone
mineral loss. Weight resistive exercises can prevent bone mineral
loss if the antigravity musculature is activated.
In animal studies, the first 40 repetitions of an exercise
stimulate greater than 95% of bone formation. Additional repetitions
do not significantly increase bone formation (Riewald 2004).
Astronauts have about the same rate of bone loss as those
on bed rest: about one percent per month.
Riewald S (2004). Bone of Contention: What Exercises Increase
Bone Strength? Strength and Conditioning Journal. 26(1): 46-47.
can thicken the hyaline cartilage on the articular surfaces of
the bone (Ingelmark & Elsholm 1948).
Joint cartilage depends on synovial fluid for its nutrition
since it has no vascularization. Synovial fluid is forced into
the cartilage surfaces when the joint is loaded, as in physical
activity. Joint cartilage functions in an elastic manner during
short term loading. The cartilage becomes temporarily deformed
when long term loading forces water out of the cartilage. It
returns to its original shape after cessation of loading when
water is again drawn into the cartilage. The alternate compression
and decompression along with the pumping of synovial fluid due
to physical activity is partly responsible for nutrition to the
Tendon and Ligament
Resistance training can increase the size and strength of
tendons and ligaments (Fahey et al. 1975). This may be due to
an increase of collagen within the connective tissue sheaths
(Laurent et al. 1978).
The elastic limit of a tendon or ligament can be enhanced
by exercise and training and can be reduced by aging and inactivity.
The elastic limits of ligament are estimated to be 12-50%, and
the elastic limits of tendon is 9-30% (Weakest at MTJ).
Junction strength failure of a bone-ligament preparation occurs
at the attachment site of the ligament. The Junction strength
failure is similar in a bone-tendon-muscle-tendon-bone preparation,
although separation may also occur at the muscletendinous junction
or in the muscle itself.
Research using animal models demonstrate that junction strength
of ligaments increases with endurance-type physical activity
and decreases with immobilization. Furthermore, damaged ligaments
regain strength faster if physical activity is performed afterwards.
Martin Paul, B.Sc. Kin., PFLC
An In Vitro setting, a ligament can stretch quite a bit. The
only ligament that can match the 50% elasticity is the ligamentum
flavum. Even then, Nachemson & Evans (1968) reported,
"Beyond this point, the stiffness increases greatly with
additional loading and the ligament failed abruptly (reached
Pmax) with little deformation. Furthermore, Butler et al (1978),
observed that beyond 4%, "small force reductions (dips)
can sometimes be observed in the loading curves for both tendons
and ligaments. These dips are caused by the early sequential
failure of a few greatly stretched fiber bundles. When sequential
failure occurs, it compromises the strength of the ligaments
and thus increases the instability of that particular joint.
Fung (1981), goes on to add that the upper limit for physiological
strain in tendons and ligaments is from 2 to 5%. Finally, Kear
& Smith (1975) findings suggest that "normal activity
of a tendon in vivo is subjected to less than one fourth of its
- Butler, D.L., Groods, E.S., and Noyes, F. R.: Biomechanics
of Ligaments and Tendons. Exerc. Sport Sci. Rev., 6:125, 1978.
- Fung, Y.C.B.: Biomechanics: Mechanical Properties of Living
Tissues. New York, Springer Verlag, 1981, p.222.
- Kear, M., and Smith, R.N.: A method for recording tendons
strain in sheep during locomotion. Acta Orthop. Scand., 46:896,
- Nachemson, A.L., and Evans, J.H.: Some mechanical properties
of the third human lumbar interlaminar ligament (ligamentum flavum).
J. Biomech., 1:211, 1968.