Exercise-Associated Muscle Cramps: Difference between revisions

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The pathophysiology causing EAMC is most likely due to muscle fatigue, It has been found that athletes who are returning to competition or beginning the functional return to sport phase of rehabilitation after injury are particularly vulnerable to EAMC. These athletes are prone to experience early muscle fatigue, to be less acclimatized to hot conditions, and to have diminished sweating efficiency, thereby raising the potential to develop EAMC.<ref>Miller KC, Stone MS, Huxel KC, Edwards JE. [https://journals.sagepub.com/doi/abs/10.1177/1941738109357299 Exercise-associated muscle cramps: causes, treatment, and prevention]. Sports health. 2010 Jul;2(4):279-83.</ref> Proper rehabilitation after an injury will prevent overstressing while ensuring adequate sport-specific conditioning prior to return to sports.<ref name=":4" />
The pathophysiology causing EAMC is most likely due to muscle fatigue, It has been found that athletes who are returning to competition or beginning the functional return to sport phase of rehabilitation after injury are particularly vulnerable to EAMC. These athletes are prone to experience early muscle fatigue, to be less acclimatized to hot conditions, and to have diminished sweating efficiency, thereby raising the potential to develop EAMC.<ref>Miller KC, Stone MS, Huxel KC, Edwards JE. [https://journals.sagepub.com/doi/abs/10.1177/1941738109357299 Exercise-associated muscle cramps: causes, treatment, and prevention]. Sports health. 2010 Jul;2(4):279-83.</ref> Proper rehabilitation after an injury will prevent overstressing while ensuring adequate sport-specific conditioning prior to return to sports.<ref name=":4" />


Unfortunately, there are no proven strategies for the prevention of exercise-associated muscle cramps. However, regular stretching using post- isometric relaxation techniques, a dynamic warm-up consisting of movements designed to actively prepare the muscle for performance, correction of biomechanical imbalances and posture, mental preparation for a game, and avoidance of provocative drugs could also be effective techniques.<ref name=":2" /> Other strategies, like neuromuscular reeducation including eccentric muscle strengthening in training programs, may help prevent EAMC. In a case report, persistent hamstring EMAC was eliminated when the triathlete incorporated gluteal strengthening exercise into his training regimen.<ref>Wagner T, Behnia N, Ancheta WK, Shen R, Farrokhi S, Powers CM. [https://www.jospt.org/doi/abs/10.2519/jospt.2010.3110 Strengthening and neuromuscular reeducation of the gluteus maximus in a triathlete with exercise-associated cramping of the hamstrings]. journal of orthopaedic & sports physical therapy. 2010 Feb;40(2):112-9.</ref>  Maintaining sufficient carbohydrate reserves during a competition to reduce the likelihood of fatigue, or treating myofascial trigger points, are speculative.<ref>Armstrong S, Cross T. [https://endocrinologytoday.com.au/2013/november/regular-series/exercise-associated-muscle-cramps Exercise-associated muscle cramps.]</ref>
Unfortunately, there are no proven strategies for the prevention of exercise-associated muscle cramps. However, regular stretching using post- isometric relaxation techniques, a dynamic warm-up consisting of movements designed to actively prepare the muscle for performance, correction of biomechanical imbalances and posture, mental preparation for a game, and avoidance of provocative drugs could also be effective techniques.<ref name=":2" /> Other strategies, like neuromuscular reeducation including eccentric muscle strengthening in training programs, may help prevent EAMC. In a case report, persistent hamstring EMAC was eliminated when the triathlete incorporated gluteal strengthening exercise into his training regimen.<ref>Wagner T, Behnia N, Ancheta WK, Shen R, Farrokhi S, Powers CM. [https://www.jospt.org/doi/abs/10.2519/jospt.2010.3110 Strengthening and neuromuscular reeducation of the gluteus maximus in a triathlete with exercise-associated cramping of the hamstrings]. journal of orthopaedic & sports physical therapy. 2010 Feb;40(2):112-9.</ref>  Maintaining sufficient carbohydrate reserves during a competition to reduce the likelihood of fatigue, or treating myofascial trigger points, are also effective.<ref>Armstrong S, Cross T. [https://endocrinologytoday.com.au/2013/november/regular-series/exercise-associated-muscle-cramps Exercise-associated muscle cramps.]</ref>


== References  ==
== References  ==

Revision as of 09:39, 4 December 2020

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Introduction[edit | edit source]

Exercise-associated muscle cramps

The muscle cramping that happens during exercise is called Exercise-Associated muscle cramps (EAMC). It is defined as a syndrome of involuntary painful skeletal muscle spasms that happens during or immediately after a workout.[1] During cramping, Skeletal or voluntary muscle contracts strongly and unable to relax resulting in EAMS. It occurs as localized muscle cramping that happens spasmodically in various exercising muscle groups, usually the calf, hamstring, or quadriceps muscles. The calf muscles are the foremost commonly affected.[2] The pain and disability that results usually limits affected limb movement, though the condition normally resolves without intervention. Resolution can take from a couple of seconds to minutes, but the afflicted part is non-functional during this time and perhaps for some time afterward.[3]

Exercise-associated muscle cramping (EAMC) is a very common condition that needs medical attention during sporting events. The incidence of EAMCs increases with higher frequency, intensity, and duration of the exercise, and are especially prevalent among athletes who participate in long-distance endurance events, like triathlon and marathon or ultra-marathon distance running, and it is also seen in many other sports, including basketball, the varied football codes, tennis, cricket, and cycling, etc.[2][4]

Prevalence[edit | edit source]

The prevalence of EAMC has been documented for triathletes (67%) runners [5] (roughly around 30% to 50%), rugby players (52%), and cyclists (60%)[6][7] Despite the high prevalence of EAMC, its risk factors, pathophysiology, management, and prevention aren't completely understood.[2] Cramps seem to be more prevalent in muscles that cross two joints, and athletes who cramp have been shown to have a lower threshold frequency for cramping (15 Hz) than non–cramp-prone individuals (25 Hz). The threshold frequency is the minimum frequency of excitation required to stimulate a muscle cramp. The fact that cramp-prone individuals have lower threshold frequency for the onset of EAMC supports the validity of a neurological origin of cramps.[3]

Risk Factors[edit | edit source]

The risk factors related to EAMC in endurance athletes include high-intensity running, long-distance running (> 30 km), subjective muscle fatigue, all of which are intense and exhaustive physical efforts. Other risk factors found were older age, a longer history of running, higher body mass index (BMI), shorter daily stretching time, irregular stretching habits, competing at a faster race pace than training pace, and a positive family history of cramping.[3][8] Factors related to a history of EAMC included underlying chronic disease (including the cardiovascular, respiratory, gastrointestinal, and nervous system, kidney, bladder, and hematological diseases), as well as cancer, allergies, regular medication use, and past history of injury. Experienced runners are also at higher risk.[9]

Aetiology[edit | edit source]

There are two theories about the origin of EAMC. The older one is based on “dehydration” and “electrolyte imbalance” theory (water-salt balance), and the more recent one is the “altered neuromuscular control” theory (neurological origin).[9] Traditional theories of cramping during exercises such as dehydration, electrolyte loss, metabolic accumulation, and heat accumulation, do not seem to be the main causes of EAMC. Of all theories known regarding causes of EAMC, a neurological origin is supported by the most robust body of literature.[10]

Altered Neuromuscular Control Theory[edit | edit source]

Abnormal spinal control of motor neuron function during Exercise-associated muscle cramp

The neuromuscular theory proposes that muscle overload and muscle fatigue resulting in an imbalance between excitatory and inhibitory impulses from muscle spindles and Golgi tendon organs (GTOs) respectively. This occurs when the muscle contracts in an already-shortened position. The reduced tension in the muscle-tendon likely decreases the inhibitory feedback from GTO afferents, thereby predisposing muscle cramping from the imbalance between inhibitory and excitatory drives to the alpha motor neuron.[3] This enhanced excitability at the spinal level which results in a rise in alpha motor neuron discharge to the muscle fibers, producing localized muscle cramps.[11][12] EAMC usually occurs more frequently at the end of competitions and physical work and when the muscle contracts while it is already shortened. Stretching, the primary treatment for acute EAMC is assumed to alleviate  EAMC via autogenic inhibition.[12] Stretching increases the strain within the muscle’s tendon, resulting in GTO activation and a rise in inhibition of the alpha motor neuron, which can restore the physiological relationship between excitatory impulses and inhibitory impulses to α motor neuron.[13] Muscle fatigue is a continuum than a condition. It's likely that the amount of fatigue required to elicit cramping is unique to each and every athlete.[9][14]

Signs and Symptoms[edit | edit source]

EAMC can be identified clinically by acute pain, stiffness, visible bulging or knots in the muscle, and possible soreness which will occur suddenly with no warning and lasts for several days.[15][16] The injured muscles often appear to be randomly involved, and as one bundle of muscle fibers relax, the adjacent bundle contracts, giving the impression that the spasms wander. For example, twitches first can appear in the quadriceps and subsequently in another muscle group. Most EAMC persists for 1-3 minutes, but athletes often complain of EAMC symptoms up to eight hours after exercise.[17] This post-exercise span of increased susceptibility to EAMC has been termed as the "cramp-prone state". EAMC may be completely debilitating although in few cases EAMC does not appear to affect athletic performance.[13]

Treatment[edit | edit source]

Preventive Measures[edit | edit source]

The pathophysiology causing EAMC is most likely due to muscle fatigue, It has been found that athletes who are returning to competition or beginning the functional return to sport phase of rehabilitation after injury are particularly vulnerable to EAMC. These athletes are prone to experience early muscle fatigue, to be less acclimatized to hot conditions, and to have diminished sweating efficiency, thereby raising the potential to develop EAMC.[18] Proper rehabilitation after an injury will prevent overstressing while ensuring adequate sport-specific conditioning prior to return to sports.[12]

Unfortunately, there are no proven strategies for the prevention of exercise-associated muscle cramps. However, regular stretching using post- isometric relaxation techniques, a dynamic warm-up consisting of movements designed to actively prepare the muscle for performance, correction of biomechanical imbalances and posture, mental preparation for a game, and avoidance of provocative drugs could also be effective techniques.[9] Other strategies, like neuromuscular reeducation including eccentric muscle strengthening in training programs, may help prevent EAMC. In a case report, persistent hamstring EMAC was eliminated when the triathlete incorporated gluteal strengthening exercise into his training regimen.[19] Maintaining sufficient carbohydrate reserves during a competition to reduce the likelihood of fatigue, or treating myofascial trigger points, are also effective.[20]

References[edit | edit source]

  1. Miller KC. Exercise-associated muscle cramps. InExertional Heat Illness 2020 (pp. 117-136). Springer, Cham.
  2. 2.0 2.1 2.2 Schwellnus MP, Drew N, Collins M. Muscle cramping in athletes—risk factors, clinical assessment, and management. Clinics in sports medicine. 2008 Jan 1;27(1):183-94.
  3. 3.0 3.1 3.2 3.3 Qiu J, Kang J. Exercise associated muscle cramps—a current perspective. Arch Sports Med. 2017;1(1):3-14.
  4. Troyer W, Render A, Jayanthi N. Exercise-associated muscle cramps in the tennis player. Current Reviews in Musculoskeletal Medicine. 2020 Jul 27:1-0.
  5. Schwellnus MP. Muscle cramping in the marathon. Sports Medicine. 2007 Apr 1;37(4-5):364-7.
  6. Maughan RJ, Shirreffs SM. Muscle cramping during exercise: causes, solutions, and questions remaining. Sports Medicine. 2019 Nov 6:1-0.
  7. Maquirriain J, Merello M. The athlete with muscular cramps: clinical approach. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2007 Jul 1;15(7):425-31.
  8. Schwellnus M, Collins M, Drew N. Risk factors associated with exercise-associated muscle cramping (EAMC)–a prospective cohort study in ironman triathletes. British Journal of Sports Medicine. 2011 Apr 1;45(4):316-.
  9. 9.0 9.1 9.2 9.3 Jahic D, Begic E. exercise-associated muscle cramp-doubts about the cause. Materia Socio-Medica. 2018 Mar;30(1):67.
  10. Bergeron MF. Muscle cramps during exercise-is it fatigue or electrolyte deficit?. Current Sports Medicine Reports. 2008 Jul 1;7(4):S50-5.
  11. Miller KC. Rethinking the cause of exercise-associated muscle cramping: moving beyond dehydration and electrolyte losses. Current sports medicine reports. 2015 Sep 1;14(5):353-4.
  12. 12.0 12.1 12.2 <header> Buskard AN. Cramping in Sports: Beyond Dehydration. Strength & Conditioning Journal. 2014 Oct 1;36(5):44-52. </header>
  13. 13.0 13.1 Schwellnus MP. Cause of exercise associated muscle cramps (EAMC)—altered neuromuscular control, dehydration or electrolyte depletion?. British journal of sports medicine. 2009 Jun 1;43(6):401-8.
  14. Miller KC. The evolution of exercise-associated muscle cramp research. ACSM's Health & Fitness Journal. 2018 Jul 1;22(4):6-8.
  15. Maquirriain J, Merello M. The athlete with muscular cramps: clinical approach. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2007 Jul 1;15(7):425-31.
  16. Minetto MA, Holobar A, Botter A, Farina D. Origin and development of muscle cramps. Exercise and sport sciences reviews. 2013 Jan 1;41(1):3-10.
  17. Dickhuth HH, Rocker K, Niess A, Horstmann T. Execise-induced, persistent and generalized muscle cramps: A case report. Journal of sports medicine and physical fitness. 2002 Mar 1;42(1):92.
  18. Miller KC, Stone MS, Huxel KC, Edwards JE. Exercise-associated muscle cramps: causes, treatment, and prevention. Sports health. 2010 Jul;2(4):279-83.
  19. Wagner T, Behnia N, Ancheta WK, Shen R, Farrokhi S, Powers CM. Strengthening and neuromuscular reeducation of the gluteus maximus in a triathlete with exercise-associated cramping of the hamstrings. journal of orthopaedic & sports physical therapy. 2010 Feb;40(2):112-9.
  20. Armstrong S, Cross T. Exercise-associated muscle cramps.