Table 3 Characteristics of the included studies

Connolly 1993 [29]

6/9

Efficacy of quinine

N = 27

59 yrs.

Male 100%

Nocturnal leg cramps. Aged > 50. Foot, lower part of leg, sometimes thigh. Sleep interruption.

Coronary artery disease, Peripheral vascular disease, Hypertension, Diabetes Mellitus

Medication: diuretics

Coppin 2005 [5]

8/9

Effect of calf stretching

N = 181

75 yrs.

Male 46%

Nocturnal leg cramps, aged > 60, painful and involuntary. Muscle spasms. Disrupt sleep. Disruption. Most commonly in the leg, relief by stretching.

Renal dialysis, asthma and hypertension.

Medication: diuretics, nifedipine, salbutamol and terbutaline

Garrison 2011 [17]

9/9

The effect of magnesium in individuals with leg cramps

N = 46

69 yrs.

Male 30%

Leg cramps, aged > 50, at rest (bed or night). Legs and feet. Painful muscle contractions.

Participants with comorbidities excluded

Hallegraeff 2012 [9]

9/9

Effect of pre sleep stretching

N = 80

70 yrs.

Male 50%

Nocturnal leg cramps, aged > 55, Suddenly, episodic. Involuntary. At rest or sleep. Calf, hamstrings or foot. Muscles are tender and hard. Intense painful. From seconds to minutes. Distress. Sleep disruption. Maximum ten minutes.

Varicose veins and arthritis. Physical inactivity and inadequate stretching and reduced muscle and tendon length.

Medication: diuretics, lithium, steroids, morphine

Jansen 1997 [18]

9/9

Efficacy of hydro quinine in muscle cramps

N = 102

54 yrs.

Male 37%

Involuntary muscle contraction. Painful Sudden onset. Muscle hardening, maximum duration 10 minutes.

Not stated

Roffe 2002 [19]

8/9

The effect of magnesium in chronic non-pregnant individuals

N = 36

63 yrs.

Male 58%

Leg cramps. Painful contractions of any muscle group in the leg. Sudden onset. Successive improvement. Palpable hardening of the muscle. Distress.

Arthritis, peripheral vascular disease, varicose veins, ankle oedema

Serrao 2001 [14]

3/9

To evaluate the efficacy and safety of gabapentin in the treatment of muscle

Cramps

N = 30

54 yrs.

33%

Sudden, involuntary, painful contractions. Maximum of 10 minutes. Sleep disturbance.

Neuropathy, radiculopathy, Isaac’s syndrome, multiple sclerosis, Parkinson’s disease, vascular disease

Young 1993 [15]

1/9

The effect of naftidrofuryl in individuals with rest cramps

N = 14

61 yrs.

Male 64%

Rest cramps. Night-time cramps. Foot, calf muscles. Distress.

Not stated

Observational studies

Angeli 1996 [20]

To define the features, prevalence, and pathophysiology of therapy for muscle and small muscles cramps in cirrhotic patients.

N = 192

56 yrs.

Male 65%

A-symmetric involuntary contractions or stiffness in calves and feet. At rest or at night

Cirrhosis, vascular occlusive disease, peripheral neuropathy, diabetes mellitus, severe renal failure and postphlebitic syndrome

Baskol 2004 [21]

6/9

The prevalence of muscle cramps in non-alcoholic cirrhosis patients.

N = 65

52 yrs.

Male 57%

Muscle cramps. Aged > 50. Involuntary. Painful, visible contraction. Sudden onset. At rest or sleep. From seconds to minutes. Affects quality of life. At least once per week. Sleep disruption.

Liver cirrhosis, diuretic, alcohol use, volume depletion, hyponatremia, haemodialysis, hypothyroidism, uraemia.

Garrison 2015 [22]

Seasonally variation of symptom burden of leg cramps in the general population.

N = 31.339

69 yrs.

Male 38%

Painful involuntary muscle cramps in the legs or feet during rest. It interrupts sleep.

Motor neuron disease, radiculopathy or hereditary cramp syndromes

Garrison 2012 [16]

6/9

Evaluating the association between diuretics, statins and long-acting β2 agonist’s use.

N = 3492

69 yrs.

Male 39%

Nocturnal leg cramps. Painful legs or feet. During rest or sleep

Medication: diuretics and long-acting β2 agonists

Hawke 2013 [4]

9/9

Impact of NLC on health related quality of life.

N = 160

71 yrs.

Male 41%

Nocturnal leg cramps. Pain afterwards.

Sleep disruption. Aged >60 with sleep disruption. Reduced quality of life. Gradually lessens. Sudden, involuntary painful contraction. At night and rest. Relief by stretching.

Participants with comorbidities known to cause cramp excluded

Hawke 2013 [23]

9/9

Factors associated with night-time calf muscle cramps

N = 160

71 yrs.

Male 41%

Reduced strength dorsiflexion foot. Distress. Lesser quality of life. Interference of activities of daily living.

Hamstring tightness. Foot or leg coldness

Participants with comorbidities known to cause cramp were excluded

Hirai 2000 [24]

4/9

NLC in general population and in patients with varicose veins

N = 333

Age not stated

Male 26%

Muscle cramps. Aged >50. Intense painful with sudden onset in calf, foot or thigh. Maximum duration 10 minutes. At least once per week.

Varicose veins

Naylor 1994 [25]

5/9

Prevalence, severity and correlation with vascular diseases

N = 86

73 yrs.

Male 44%

Rest cramps. Aged > 50. Distress. Less quality of life.

Peripheral vascular disease

Nishant 2014 [26]

5/9

Prevalence of nocturnal leg cramps in LSCS patients and in general population.

N = 70

56 yrs.

Male 53%

Nocturnal cramps. Painful. Acute and involuntary. At sleep or rest. Knee flexion test might be indicative for NLC.

Amyotrophic lateral sclerosis, poliomyelitis, peripheral neuropathy, lumbar spinal radiculopathy; metabolic disorders including diabetes, pregnancy, uremia, liver cirrhosis, and hyper- and hypothyroidism; acute extracellular volume depletion including excessive perspiration, hemodialysis, diarrhea, and diuretic therapy; hereditary disorder. Hypertension, hypocalcaemia, hypokalaemia, vascular diseases.

Medications: diuretics, antidepressants, calcium blockers, statins, and steroid, nifedipine-blockers.

Oboler 1991 [27]

4/9

Prevalence and treatment regimens of NLC

N = 262

60 yrs.

Male 95%

Painful and involuntary in the calf with a visible palpable knot. At rest or sleep.

Arthritis, Peripheral vascular disease, Hypokalaemia, Coronary artery disease, Hypertension, Kidney disease, Stroke, Diabetes Mellitus, Hypocalcaemia.