Factors associated with night-time calf muscle cramps: A case-control study

Correlates of night-time and exercise-associated lower limb cramps in healthy adults

INTRODUCTION/AIMS

We explored correlates of night-time and exercise-associated lower limb cramps in participants of the 1000 Norms Project.

METHODS

A volunteer community sample of healthy people aged ≥18 y underwent assessment of motor function and physical performance, and were questioned about muscle cramps in the previous 3 mo.

RESULTS

Of 491 (221 female) participants age 18-101 y (mean: 59.12; SD: 18.03), about 1 in 3 experienced night-time lower limb cramps, and about 1 in 4 experienced exercise-associated lower limb cramps. For night-cramps, a one unit increase in Beighton score (greater whole-body flexibility) was associated with a 31% reduced odds of cramps (odds ratio [OR] = 0.69, 95% confidence interval [CI]:0.45, 0.99) and passing all three lesser-toe strength tests was associated with 50% reduced odds of cramps (OR = 0.50, 95% CI: 0.32, 0.78). For exercise-associated cramps, participants in the fourth (lowest arch) quartile of Foot Posture Index were 2.1 times (95% CI: 1.11, 3.95) more likely to experience cramps than participants in the first (highest arch) quartile. Odds of experiencing both types of cramps versus no cramps were lower with passing all three lesser-toe strength tests (OR = 0.40, 95% CI: 0.19, 0.85) and better performance in the six-minute walk test (OR = 0.997, 95% CI: 0.996, 0.998).

DISCUSSION

People who experienced both exercise-associated and night-time cramps were less functional. The association between night-time cramps with less whole-body flexibility and reduced lesser-toe flexor strength should be explored to determine causation. Planovalgus (low-arched) foot type was independently associated with exercise-associated cramps. The effectiveness of foot orthoses for secondary prevention of exercise-associated cramps in people with low-arched feet should be explored.

Non-drug therapies for the secondary prevention of lower limb muscle cramps

BACKGROUND

Lower limb muscle cramps are common and painful. They can limit exercise participation, and reduce quality of sleep, and quality of life. Many interventions are available for lower limb cramps; some are controversial or could cause harm, and often, people experience no benefit from the interventions used. This is an update of a Cochrane Review first published in 2012. We updated the review to incorporate new evidence.

OBJECTIVES

To assess the effects of non-drug, non-invasive therapies for lower limb muscle cramps.

SEARCH METHODS

In August 2018 and May 2020, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov, and reference lists of included studies. We imposed no restrictions by language or publication date.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) of non-drug, non-invasive interventions tested over at least four weeks, for lower limb muscle cramps in any group of people, except pregnant women. The primary outcome was cramp frequency. Secondary outcomes were cramp pain severity, cramp duration, health-related quality of life, quality of sleep, participation in activities of daily living, proportion of participants reporting lower limb muscle cramps, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, and cross-checked data extraction and analyses according to standard Cochrane procedures.

MAIN RESULTS

We included three trials, with 201 participants, all 50 years of age and older; none had neurological disease. All trials evaluated a form of stretching for lower limb muscle cramps. A combination of daily calf and hamstring stretching for six weeks may reduce the severity of night-time lower limb muscle cramps (measured on a 10 cm visual analogue scale (VAS) where 0 = no pain and 10 cm = worst pain imaginable) in people aged 55 years and older, compared to no intervention (mean difference (MD) -1.30, 95% confidence interval (CI) -1.74 to -0.86; 1 RCT, 80 participants; low-certainty evidence). The certainty of evidence was very low for cramp frequency (change in number of cramps per night from week zero to week six) comparing the stretching group and the no intervention group (MD -1.2, 95% CI -1.8 to -0.6; 80 participants; very low-certainty evidence). Calf stretching alone for 12 weeks may make little to no difference to the frequency of night-time lower limb muscle cramps in people aged 60 years and older (stretching group median number of cramps in the last four weeks (Md) 4, interquartile range (IQR) 8; N = 48; sham stretching group Md 3, IQR 7.63; N = 46) (U = 973.5, z = -0.995, P = 0.32, r = 0.10; 1 RCT, 94 participants; low-certainty evidence). This trial did not report cramp severity. The evidence is very uncertain about the effects of a combination of daily calf, quadriceps, and hamstring stretching on the frequency and severity of leg cramps in 50- to 60-year-old women with metabolic syndrome (N = 24). It was not possible to fully analyse the frequency data and the scale used to measure cramp severity is not validated. No study reported health-related quality of life, quality of sleep, or participation in activities of daily living. No participant in these three studies reported adverse events. The evidence for adverse events was of moderate certainty as the studies were too small to detect uncommon events. In two of the three studies, outcomes were at risk of recall bias, and tools used to measure outcomes were not validated. Due to limitations in study designs that led to risks of bias, and imprecise findings with wide CIs, we cannot be certain that findings of future studies will be similar to those presented in this review.

AUTHORS' CONCLUSIONS

A combination of daily calf and hamstring stretching for six weeks may reduce the severity of night-time lower limb muscle cramps in people aged 55 years and older, but the effect on cramp frequency is uncertain. Calf stretching alone compared to sham stretching for 12 weeks may make little or no difference to the frequency of night-time lower limb muscle cramps in people aged 60 years and older. The evidence is very uncertain about the effects of a combination of daily calf, quadriceps, and hamstring stretching on the frequency and severity of leg cramps in 50- to 60-year-old women with metabolic syndrome. Overall, use of unvalidated outcome measures and inconsistent diagnostic criteria make it difficult to compare the studies and apply findings to clinical practice. Given the prevalence and impact of lower limb muscle cramps, there is a pressing need to carefully evaluate many of the commonly recommended and emerging non-drug therapies in well-designed RCTs across all types of lower limb muscle cramps. A specific cramp outcome tool should be developed and validated for use in future research.

Association between physical activity and Nocturnal Leg Cramps in patients over 60 years old: a case-control study

Nocturnal Legs Cramps are a frequent disorder, which have a negative impact on quality of life, particularly among patients over 60 years old. Lifestyle factors such as alcohol consumption have been shown to be associated with Nocturnal Leg Cramps. This study aimed to explore the association between nocturnal leg cramps and a sedentary lifestyle among elderly patients. A case-control study was conducted with a Bayesian approach for sensitivity analysis. Patients over 60 years old consulting their family doctor were recruited in the Alsace region, France. Cases were matched with controls free from cramps for age, sex, medical history and medications known to trigger cramps. The level of physical activity was assessed using the Dijon Physical Activity Score (DPAS). We performed univariate and multivariate analyses adjusting for alcohol consumption. 272 participants were matched into 136 pairs. 11% of all were sedentary persons. Adjusting for alcohol consumption, we observed an association between Nocturnal Leg Cramps and a sedentary lifestyle OR = 9.84 (95% credibility interval [1.74; 101.9]; posterior probability 99.68%). Our findings represent an additional argument to promote physical activity to patients over 60 years old. They also highlight the need to develop and evaluate physical activity interventions in the treatment of Nocturnal Legs Cramps.

Association Between Alcohol Consumption and Nocturnal Leg Cramps in Patients Over 60 Years Old: A Case-Control Study

PURPOSE

Nocturnal leg cramps are a specific kind of cramps affecting almost one-half of patients aged 60 years and older. They reduce patients' quality of sleep and have a negative impact on their quality of life. The aim of this study was to evaluate the association between nocturnal leg cramps and the consumption of alcoholic beverages in patients aged 60 years and older attending general practices.

METHODS

Case-control study with a Bayesian approach for sensitivity analysis. Participants were voluntary ambulatory patients aged 60 years and older consulting their family doctor. They were recruited in 67 general practices across the Alsace region. Cases (patients having cramps), were matched with controls (patients free from cramps) for age, sex, medical history, and medications known to trigger cramps. Alcohol consumption was assessed through a standardized food frequency questionnaire.

RESULTS

We found an association between the global consumption of alcoholic beverages and nocturnal leg cramps (OR = 6.5, 95% credibility interval, 1.68-38.05; posterior probability 99.82%).

CONCLUSION

We identified an association between alcohol consumption and nocturnal leg cramps among patients aged 60 years and older attending general practices. These findings have implications for the prevention of cramps.

Nocturnal leg cramps: Prevalence and associations with demographics, sleep disturbance symptoms, medical conditions, and cardiometabolic risk factors

BACKGROUND

Nocturnal leg cramps (NLC) are common and poorly understood.

OBJECTIVE

To determine the prevalence of NLC and associations with cardiometabolic, sleep, and behavioral risk factors in the US population.

DESIGN

Cross-sectional epidemiology.

PARTICIPANTS

National Health and Nutrition Examination Survey, 2005-2006 and 2007-2008 waves.

MAIN OUTCOME(S) AND MEASURE(S)

NLC were assessed with, "In the past month, how often did you have leg cramps while trying to sleep?" Responses were categorized as None, Mild, or Moderate-Severe. Demographics, medical history, sleep disturbances, and cardiometabolic risk factors were evaluated using the 2005-2006 dataset. Variables that demonstrated significant relationships to NLC after adjusting for age, sex, education, and BMI were assessed in the 2007-2008 dataset. Variables that were still significant were entered into a forward stepwise regression model combining both waves, to determine which variables best explained the variance in NLC.

RESULTS

Prevalence was 24-25% reporting mild and 6% reporting moderate-severe NLC. NLC increased with age, lower education, unemployment, shorter sleep duration, all assessed sleep symptoms (nocturnal "leg jerks", snoring, snorting/gasping, difficulty falling asleep, difficulty maintaining sleep, non-restorative sleep, sleepiness, use of sleep medications), higher BMI, smoking, medical history (hypertension, heart failure, angina, stroke, arthritis, respiratory disease, and cancer), depression symptoms, and biomarkers (CRP, HbA1c, calcium, cadmium, red blood cells). Stepwise analysis showed that moderate-severe nocturnal leg cramps were associated with (in decreasing order of partial R2): leg jerks, poor overall health, arthritis, difficulty falling asleep, age, nonrestorative sleep, red blood cell count, lower education, angina, and difficulty maintaining sleep.

CONCLUSIONS AND RELEVANCE

Based on this first large, representative study, NLC occurring >5x per month are reported by 6% of the adult US population. Sleep disturbance symptoms and health conditions are associated with higher frequency of NLC, suggesting that NLC is a marker, and possibly contributor, to poor sleep and general health.

Criteria in diagnosing nocturnal leg cramps: a systematic review

BACKGROUND

Up to 33% of the general population over 50 years of age are affected by nocturnal leg cramps. Currently there are no generally accepted clinical characteristics, which identify nocturnal leg cramps. This study aims to identify these clinical characteristics and to differentiate between them and the characteristics of restless leg syndrome and periodic limb disorder.

METHOD

A systematic literature study was executed from December 2015 to May 2016. This study comprised of a systematic literature review of randomized clinical trials, observational studies on nocturnal and rest cramps of legs and other muscles, and other systematic and narrative reviews. Two researchers independently extracted literature data and analyzed this using a standardized reviewing protocol. Modified versions of the Cochrane Collaboration tools assessed the risk of bias. A Delphi study was conducted to assess agreement on the characteristics of nocturnal leg cramps.

RESULTS

After systematic and manual searches, eight randomized trials and ten observational studies were included. On the basis of these we identified seven diagnostic characteristics of nocturnal leg cramps: intense pain, period of duration from seconds to maximum 10 minutes, location in calf or foot, location seldom in thigh or hamstrings, persistent subsequent pain, sleep disruption and distress.

CONCLUSION

The seven above characteristics will enhance recognition of the condition, and help clinicians make a clear distinction between NLC and other sleep-related musculoskeletal disorder among older adults.

Are Electrically Induced Muscle Cramps Able to Increase the Cramp Threshold Frequency, When Induced Once a Week?

The cramp threshold frequency (CTF) is known to be positively correlated with the individual cramp susceptibility. Here we assessed CTF changes after two bouts of electrically induced muscle cramps (EIMCs). The EIMCs (6×5 sec) were unilaterally induced twice (separated by one week) in the gastrocnemius of an intervention group (n=8), while 5 participants served as control. The CTF increased from 25.1±4.6 Hz at baseline to 31.4±9.0 Hz and 31.7±8.5 Hz 24 h after bout 1 and 2 (P<0.05). Thereafter, the CTF declined following both bouts to reach values of 28.0±6.7 Hz and 29.1±7.7 Hz after 72 h after bout 1 and 2. Creatine kinase (CK) activity and perceived discomfort during cramps was lower after bout 2 (P<0.05). CTF, CK, and discomfort did not change in CG. That is, a single bout of EIMCs induces a 24 h CTF increment and a second bout sustains this effect, while perceived discomfort and muscle damage decreases. This short term effect may help athletes to reduce the cramp susceptibility for an important match.

Prospective study of muscle cramps in Charcot-Marie-tooth disease

INTRODUCTION

This study aims to assess the frequency, location, severity, duration, and fluctuation over time of muscle cramps in Charcot-Marie-Tooth disease (CMT).

METHODS

Inherited Neuropathies Consortium Contact Registry participants recorded the occurrence and characteristics of muscle cramps using an 11-question survey administered 3 times over 8 weeks.

RESULTS

A total of 110 adult patients with CMT completed the survey. Weekly cramp frequency was 9.3 (SD 12.3), and 23% had daily muscle cramps. Twenty-two percent reported a significant impact on quality of life. Over 8 weeks, the daily frequency and severity of muscle cramps did not change significantly.

CONCLUSIONS

Patients with CMT have muscle cramps that vary little over an 8-week period, and they may interfere with quality of life. These data may be useful in the planning of clinical trials of agents to treat adults with CMT-associated muscle cramps.

Paroxysmal dyskinesia suspected as canine epileptoid cramping syndrome in a young Yorkshire terrier dog

A 9-month-old intact female Yorkshire terrier dog was presented with episodic partial seizure-like cramping of the limbs. The patient's episodes began six months previously; the interval between episodes became shorter, and the duration of the episodes increased. Various tests including neurologic examination, blood examination, abdominal radiography, ultrasonographic examination, angiographic computed tomography (CT) and brain magnetic resonance imaging (MRI) detected no remarkable changes. After these tests were conducted, the patient's condition was suspected to be canine epileptoid cramping syndrome (CECS), which could be a form of paroxysmal dyskinesia (PD), and as a trial therapy, Science Diet k/d (Hill's Pet Nutrition, Topeka, KS, U.S.A.) was prescribed. The clinical signs were dramatically reduced after diet therapy, and we diagnosed the patient with CECS. This is the first case report of CECS in a Yorkshire terrier dog.