Leg-crossing to prevent syncope
Date First Published:
April 21, 2011
Last Updated:
April 15, 2013
Report by:
Nele Pauwels, Staff member Centre of Expertise (Belgian Red Cross-Flanders)
Search checked by:
Emmy De Buck , Belgian Red Cross-Flanders
Three-Part Question:
In [individuals who suffer from orthostatic hypotension], does [leg-crossing] prevent [transient loss of consciousness or syncope]?
Clinical Scenario:
A 70-year-old man encountered several episodes of hypotension when standing after bending over to tie his shoes. Last time, he lost consciousness transiently. He asks you for an easy way to prevent passing out, as he lives alone. You once heard about the effect of leg crossing and you wonder if leg crossing actually prevents syncope caused by orthostatic hypotension.
Search Strategy:
1. The Cochrane library - including the Cochrane Central Register of Controlled Trials (CENTRAL) - from date of inception to end of August 2012 using the Wiley interface: (MeSH descriptor Syncope explode all trees OR MeSH descriptor Hypotension, Orthostatic explode all trees OR fainting) AND leg
2. MEDLINE from date of inception to end of August 2012 via Pubmed interface: (\"Hypotension, Orthostatic\"[Mesh] OR “syncope”[Mesh]) AND leg AND cross*
3. EMBASE from date of inception to end of August 2012 via Embase.com interface: (‘syncope’/exp OR ‘orthostatic hypotension’/exp) AND leg AND cross*
2. MEDLINE from date of inception to end of August 2012 via Pubmed interface: (\"Hypotension, Orthostatic\"[Mesh] OR “syncope”[Mesh]) AND leg AND cross*
3. EMBASE from date of inception to end of August 2012 via Embase.com interface: (‘syncope’/exp OR ‘orthostatic hypotension’/exp) AND leg AND cross*
Outcome:
1. The Cochrane library: 34 Cochrane reviews and 0 clinical trials were found. None of them were relevant to the clinical question.
2. MEDLINE: 35 studies were found, 9 of which were relevant to the clinical question.
3. EMBASE: 69 studies were found, no additional paper was selected.
In total, 9 papers were retained and summarised in the table.
2. MEDLINE: 35 studies were found, 9 of which were relevant to the clinical question.
3. EMBASE: 69 studies were found, no additional paper was selected.
In total, 9 papers were retained and summarised in the table.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Leg crossing improves orthostatic tolerance in healthy subjects: a placebo-controlled crossover study. Krediet CT, van Lieshout JJ, Bogert LW et al. 2006, The Netherlands | 9 healthy subjects (median age: 25 yr [range: 20 - 41]) subjected to the induction of presyncope via head-up tilting with incremental lower body negative pressure | Randomised crossover trial with comparison a) leg crossing without muscle tension vs. b) standing (level of evidence: 2b) |
Orthostatic tolerance | 34 ± 2 min vs. 26 ± 2 min (P < 0.001) (Mean ± SEM) | Small and young study population; mode of randomisation is not described (unclear randomisation) |
| Blood pressure | Systolic: 81 ± 4 mm Hg vs. 72 ± 7 mm Hg (NS) (mean ± SEM); Diastolic: 55 ± 2 mm Hg vs. 48 ± 5 mm Hg (NS) (mean ± SEM) | ||||
| Heart rate | 116 ± 7 beats/min vs. 107 ± 10 beats/min (P = 0.001) (mean ± SEM) | ||||
| Hemodynamic effects of leg crossing and skeletal muscle tensing during free standing in patients with vasovagal syncope. van Dijk N, de Bruin IG, Gisolf J et al. 2005, The Netherlands | 88 patients with vasovagal syncope (median age 38.5 yr [range: 16 - 85]) | Within subjects design with comparison a) leg crossing with muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Systolic: 130.9 ± 16.9 mm Hg vs. 125.3 ± 16.1 mm Hg (P < 0.001) (mean ± SD); Diastolic: 75.0 ± 10.7 mm Hg vs.73.8 ± 10.3 mm Hg (P < 0.01) (mean ± SD) | Young study population; patients diagnosed for vasovagal syncope; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Heart rate | 82.2 ± 14.9 beats/min vs. 82.8 ± 15.3 beats/min (NS) (mean ± SD) | ||||
| Management of vasovagal syncope: controlling or aborting faints by leg crossing and muscle tensing. Krediet CT, van DN, Linzer M et al. 2002, The Netherlands | 21 patients with vasovagal syncope (mean age 41 yr [Range: 17 – 74]) | Within subjects design with comparison a) leg crossing with muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Systolic: 106 ± 16 mm Hg vs. 65 ± 13 mm Hg (P < 0.001) (mean ± SD); Diastolic: 65 ± 10 mm Hg vs. 43 ± 9 mm Hg (P < 0.001) (mean ± SD) | Small and young study population; patients diagnosed for vasovagal syncope; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Heart rate | 82 ± 15 beats/min vs. 73 ± 22 beats/min (P < 0.01) (mean ± SD) | ||||
| Leg crossing with muscle tensing, a physical counter-manoeuvre to prevent syncope, enhances leg blood flow. Groothuis JT, van DN, Ter WW et al. 2007, The Netherlands | 13 healthy subjects (age 23.6 yr ± 1.0) (mean ± SEM) | Within subjects design with comparison a) leg crossing with muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Mean arterial pressure: 102.5 ± 3.4 vs. 89.3 ± 2.5 (P < 0.05) (mean ± SEM) | Small and young study population; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Heart rate | 86.4 ± 3.3 beats/min vs. 91.8 ± 3.2 beats/min (P < 0.05) (mean ± SEM) | ||||
| Effects of leg muscle pumping and tensing on orthostatic arterial pressure: a study in normal subjects and patients with autonomic failure. Ten Harkel AD, van Lieshout JJ, Wieling W. 1994, The Netherlands | 13 subjects in total: 5 patients with orthostatic hypotension (age 45 yr [range 20 - 65]) and 8 healthy subjects (age 30 yr [range 28 - 34]) |
Within subjects design with comparison a) leg crossing without muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Systolic: increase with 18 ± 18 mm Hg in patients with orthostatic hypotension (P < 0.05) and increase with 4 ± 7 mm Hg in healthy subjects (NS); Diastolic: increase with 10 ± 11 mm Hg in patients with orthostatic hypotension (P < 0.05) and increase with 0 ± 3 mm Hg in healthy subjects (NS) | Small and young study population; indirect outcome (cardiovascular responses instead of orthostatic tolerance); possible carry-over effect since 2 counter-pressure manoeuvres (tiptoeing and leg crossing) were performed in random order with 1 minute of quiet standing in between) |
| Heart rate | Decrease of 4 ± 5 beats/min in patients with orthostatic hypotension (NS) and decrease with 6 ± 4 beats/min in healthy subjects (P < 0.05) | ||||
| Central and cerebrovascular effects of leg crossing in humans with sympathetic failure. Harms MP, Wieling W, Colier WN et al. 2010, The Netherlands | 16 subjects in total: 8 patients with sympathetic failure (age range 37 – 67 yr) and 8 healthy subjects (age-matched) |
Within subjects design with comparison a) leg crossing without muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Mean arterial pressure: 72 mm Hg [52 ; 89] vs. 58 mm Hg [42 ; 79] in patients with orthostatic hypotension (P < 0.05) and 90 mm Hg [74 ; 94] vs. 84 mm Hg [70 ; 95] in healthy subjects (NS) (Median [range]) | Small and young study population; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Heart rate | 75 beats/min [59 ; 92] vs. 75 beats/min [64 ; 97] in patients with orthostatic hypotension (NS); 71 beats/min [58 ; 79] vs. 74 beats/min [72 ; 86] in healthy subjects (NS) (Median [range]) | ||||
| Physical manoeuvres for combating orthostatic dizziness in autonomic failure. van Lieshout JJ, Ten Harkel AD, Wieling W. 1992, The Netherlands | 13 subjects in total: 7 patients with orthostatic hypotension (age range 18-65) and 6 healthy subjects (age range 28 -34 yr) |
Within subjects design with comparison a) leg crossing without muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Systolic: 95 ± 13 mm Hg vs. 75 ± 13 mm Hg in patients with orthostatic hypotension (P = 0.006) and 120 ± 7 mm Hg vs. 116 ± 15 mm Hg in healthy controls (P = 0.55) (mean ± SD); Diastolic: 60 ± 7 mm Hg vs. 50 ± 7 mm Hg in patients with orthostatic hypotension (P = 0.01) and 71 ± 3 mm Hg vs. 71 ± 8 mm Hg in healthy controls (P = 0.56) (mean ± SD) | Small and young study population; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Role of physical countermaneuvers in the management of orthostatic hypotension: efficacy and biofeedback augmentation. Bouvette CM, McPhee BR, Opfer-Gehrking TL et al. 1996, USA | 9 patients with orthostatic hypotension (age range 58 ± 18 yr) (mean ± SD) | Within subjects design with comparison a) leg crossing with muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Systolic: increase with 24.8 ± 19.0 mm Hg (P = 0.001) (mean ± SD) | Small and young study population; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Usefulness of physical maneuvers for prevention of vasovagal syncope. Kim KH, Cho JG, Lee KO et al. 2005, Korea | 48 subjects in total: 27 patients with vasovagal syncope (age 44.5 ± 15.3 yr) and 21 healthy subjects (age 28.6 ± 6.3 yr) (mean ± SD) |
Within subjects design with comparison a) leg crossing with muscle tension vs. b) standing (level of evidence: 2b) | Blood pressure | Net change of systolic: 8.0 ± 5.8 mmHg for patients with vasovagal syncope (P < 0.05) and 8.7 ± 5.7 mmHg for healthy subjects (P < 0.05) (mean ± SD); Net change of diastolic: 1.6 ± 4.8 mmHg for patients with vasovagal syncope (NS) and 1.1 ± 4.9 mmHg for healthy subjects (NS) (mean ± SD) | Small and young study population; no clear description of body posture of study population when measuring baseline measurement; indirect outcome (cardiovascular responses instead of orthostatic tolerance) |
| Heart rate | Change with 5.7 ± 10.5 beats/min for patients with vasovagal syncope (NS) and 3.7 ± 5.3 for healthy subjects (P <0.05) (mean ± SD) |
Author Commentary:
Syncope is usually of rapid onset, short duration and spontaneous complete recovery. Although squatting might be beneficial to prevent syncope, it is may not be suitable for old people. In contrast, leg crossing is easy to perform.
Bottom Line:
Leg crossing is a simple manoeuvre that has clinical benefit for people who experience orthostatic hypotension.
Level of Evidence:
Level 2: Studies considered were neither 1 or 3
References:
- Krediet CT, van Lieshout JJ, Bogert LW et al.. Leg crossing improves orthostatic tolerance in healthy subjects: a placebo-controlled crossover study.
- van Dijk N, de Bruin IG, Gisolf J et al.. Hemodynamic effects of leg crossing and skeletal muscle tensing during free standing in patients with vasovagal syncope.
- Krediet CT, van DN, Linzer M et al.. Management of vasovagal syncope: controlling or aborting faints by leg crossing and muscle tensing.
- Groothuis JT, van DN, Ter WW et al.. Leg crossing with muscle tensing, a physical counter-manoeuvre to prevent syncope, enhances leg blood flow.
- Ten Harkel AD, van Lieshout JJ, Wieling W.. Effects of leg muscle pumping and tensing on orthostatic arterial pressure: a study in normal subjects and patients with autonomic failure.
- Harms MP, Wieling W, Colier WN et al.. Central and cerebrovascular effects of leg crossing in humans with sympathetic failure.
- van Lieshout JJ, Ten Harkel AD, Wieling W. . Physical manoeuvres for combating orthostatic dizziness in autonomic failure.
- Bouvette CM, McPhee BR, Opfer-Gehrking TL et al.. Role of physical countermaneuvers in the management of orthostatic hypotension: efficacy and biofeedback augmentation.
- Kim KH, Cho JG, Lee KO et al.. Usefulness of physical maneuvers for prevention of vasovagal syncope.