|What this study adds: Nightly stretching of the calves and hamstrings reduces the frequency of nocturnal leg cramps in older adults. Nightly stretching also lessens the pain associated with any cramps that continue to occur.
The cause of nocturnal leg cramps is unknown. However, several possible causes and precipitating factors have been hypothesised. Abnormal excitability of motor nerves, perhaps due to electrolyte imbalance, may be a contributing mechanism (Monderer et al 2010). Diuretics, steroids, morphine, and lithium are also reported to cause nocturnal cramps, as can repetitive movements during sport (Butler et al 2002, Kanaan and Sawaya 2001, Monderer et al 2010). Conversely, physical inactivity has been proposed as a cause, with inadequate stretching leading to reduced muscle and tendon length (Monderer et al 2010, Sontag and Wanner 1988).
Quinine and hydroquinine are moderately effective in reducing the frequency and severity of nocturnal leg cramps (El-Tawil et al 2010, van Kan et al 2000), perhaps by decreasing the excitability of the motor end plate and thereby increasing the refractory period of a muscle (Vetrugno et al 2007). However, quinine can have important side effects, especially for women, such as: thrombocytopenia, hepatitis, high blood pressure, tinnitus, severe skin rash, and haemolytic uremic syndrome (Aronson 2006, Inan-Arslan et al 2006).
Although other medications have been used to treat nocturnal leg cramps such as magnesium, Vitamin B Complex Forte, calcium, and vitamin E, none of these appears to be effective (Anonymous 2007, Daniell 1979).
Moreover, stretching techniques can foster a resilient attitude toward recovery in patients with nocturnal leg cramps by promoting a ‘bounce back and move on’ behavioural strategy (Norris et al 2008), because they give patients a strategy to seek immediate relief.
Each stretch was performed a total of three times, with 10 seconds of relaxation between each stretch. Stretching of both legs was done within three minutes.
Our results showed that six weeks of nightly stretching of the calf and hamstring muscles significantly reduced the frequency and severity of nocturnal leg cramps in older people. The best estimate of the average effect of stretching on the frequency of cramps was a reduction of about one cramp per night.
The stretches reduced the severity of the pain that occurred with the nocturnal leg cramps by 1.3 cm on a 10-cm visual analogue scale.