Electrical stimulation cramp threshold frequency correlates well with the occurrence of skeletal muscle cramps

Abstract

The minimum electrical stimulation frequency (HZ) at which a muscle cramps is termed threshold frequency (TF). TF is theorized to represent one's predisposition to cramping; however, TF and cramp occurrence have never been correlated. We hypothesized that TF would be lower in individuals with a cramp history and lower on the second of two days of testing; genetics may partially explain this lower TF. Cramp TF was measured in 19 subjects with (Group 1), and 12 subjects without (Group 2), a cramp history. Group 1 had a lower TF (14.9 +/- 1.3 vs. 25.5 +/- 1.6 HZ; P < 0.001) and a higher family history of cramping than Group 2 (89% vs. 27%; P < 0.001). TF was lower on day 2 (18.3 +/- 0.26 HZ) than day 1 (19.7 +/- 0.25 HZ; P = 0.03). Lower TFs are correlated with cramp history, supporting the inference that lower TFs may represent increased predisposition toward cramping. TF may be used to identify individuals at risk of cramping.

Prevalence and Morbidity Associated With Muscle Cramps in Patients With Cirrhosis

“…37 Prior studies suggest that threshold frequency is generally indicative of an individual's predisposition to muscle cramping. 37,38 Because of the lack of an effective therapy and high placebo response rates, there is confusion with regard to optimal therapy. The novel use of threshold frequency as a tool to quantitatively measure the response to various therapeutic interventions for muscle cramps is thus highly desirable.…”

Initial Electrical Stimulation Frequency and Cramp Threshold Frequency and Force

“…P ercutaneous electrical stimulation is a reliable and generally well-tolerated model for inducing muscle cramps and might be helpful for studying the pathogenesis and treatment of skeletal muscle cramps. 1,2 Most researchers studying electrically induced muscle cramps [1][2][3][4] have used a modification of the model described by Bertolasi et al, 5 who used trains of electrical stimuli consisting of 40 stimuli beginning at an initial electrical stimulation frequency of 1 Hz to induce cramps in the flexor hallucis brevis. Modifications to this technique include using an initial stimulation frequency of 4 Hz, increasing stimulation frequency in 2-Hz increments, and separating stimulations by 60 seconds of rest.…”

“…Modifications to this technique include using an initial stimulation frequency of 4 Hz, increasing stimulation frequency in 2-Hz increments, and separating stimulations by 60 seconds of rest. [1][2][3] The minimum stimulation frequency at which a cramp occurs is termed threshold frequency (TF). In a previous investigation, we 3 reported that individuals with a history of muscle cramping have a lower TF than those who report no history of cramping.…”

“…[1][2][3] The minimum stimulation frequency at which a cramp occurs is termed threshold frequency (TF). In a previous investigation, we 3 reported that individuals with a history of muscle cramping have a lower TF than those who report no history of cramping. This suggests that lower TF might be associated with the occurrence of cramp symptoms and adds validity to the assumption that lower TFs represent a greater propensity to cramp.…”

“…Scientists have used initial frequencies of 1 Hz, 5,7 4 Hz, [1][2][3]6 5 Hz, 7 and 10 Hz 4 to study muscle cramping. Starting at a low frequency ensures a reliable measurement of TF by preventing overshooting cramp TF because some patients develop cramps at low stimulation frequencies (eg, 5 Hz).…”