Static Stretch Performed After Strength Training Session Induces Hypotensive Response in Trained Men

Stretch syncope in humans: Evidence for symptomatic neural reflex hypotension triggered by stretching of shoulder and upper back muscles

BACKGROUND

Stretch-induced syncope (SIS) is a poorly understood condition that we hypothesized may be due to a neural reflex hypotensive response triggered by stretching of shoulder/upper back muscles.

OBJECTIVE

This study compared the impact of shoulder/upper back stretching on heart rate (HR) and blood pressure (BP) responses in patients with SIS, with the findings in controls evaluated for symptoms unrelated to stretching.

METHODS

The study population comprised 33 individuals: 9 otherwise healthy patients with SIS and 24 healthy controls. Beat-to-beat HR and systolic BP (SBP) and mean arterial pressure (MAP) responses were recorded during active standing (AS), Valsalva maneuver, and respiratory sinus arrhythmia. Patients with SIS also underwent carotid sinus massage while seated. In addition, all subjects undertook an active shoulder/upper back extension maneuver for approximately 10-15 seconds while keeping forearms still and breathing normally.

RESULTS

Stretch elicited a drop in BP to nadir values of SBP and MAP (95.9 ± 24.2 and 76.2 ± 17.3 mm Hg in patients with SIS and controls, respectively). However, stretch-induced SBP and MAP decrease was greater in patients with SIS (P=.003 and P=.013). Further, the ratio of the ΔHR increase to ΔBP drop was lower (P=.001) during stretch-induced hypotension than during comparable hypotension induced immediately after AS.

CONCLUSION

Shoulder/upper back stretching induces a transient hypotensive response in humans, with BP fall greater in patients with SIS than in controls. Further, compensatory HR increment associated with stretch-induced hypotension was less in both patients with SIS and controls than comparable transient BP fall with AS, suggesting chronotropic restraint. Thus, SIS results from exaggerated stretch-induced vasodepression with limited compensatory tachycardia favoring a neural reflex mechanism.

Effects of Manual Therapies and Resistance Exercise on Postexercise Hypotension in Women With Normal Blood Pressure

ABSTRACT

Monteiro, ER, Pescatello, LS, Winchester, JB, Corrêa Neto, VG, Brown, AF, Budde, H, Marchetti, PH, Silva, JG, Vianna, JM, and Novaes, JdS. Effects of manual therapies and resistance exercise on postexercise hypotension in women with normal blood pressure. J Strength Cond Res 36(4): 948-954, 2022-The purpose of this investigation was to examine the acute effects of resistance exercise (RE) and different manual therapies (static stretching and manual massage [MM]) performed separately or combined on blood pressure (BP) responses during recovery in women with normal BP. Sixteen recreationally strength-trained women (age: 25.1 ± 2.9 years; height: 158.9 ± 4.1 cm; body mass: 59.5 ± 4.9 kg; body mass index: 23.5 ± 1.9 kg·m-2; baseline systolic BP median: 128 mm Hg; and baseline diastolic BP median: 78 mm Hg) were recruited. All subjects performed 6 experiments in a randomized order: (a) rest control (CON), (b) RE only (RE), (c) static-stretching exercise only (SS), (d) MM only, (e) RE immediately followed by SS (RE + SS), and (f) RE immediately followed by MM (RE + MM). RE consisted of 3 sets of bilateral bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. Static stretching and MM were applied unilaterally in 2 sets of 120 seconds to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic BP were measured before (rest) and every 10 minutes for 60 minutes following (Post 10-60) each intervention. There were significant intragroup differences for RE in Post-50 (p = 0.038; d = -2.24; ∆ = -4.0 mm Hg). Similarly, SBP intragroup differences were found for the SS protocol in Post-50 (p = 0.021; d = -2.67; ∆ = -5.0 mm Hg) and Post-60 (p = 0.008; d = -2.88; ∆ = -5.0 mm Hg). Still, SBP intragroup differences were found for the MM protocol in Post-50 (p = 0.011; d = -2.61; ∆ = -4.0 mm Hg) and Post-60 (p = 0.011; d = -2.74; ∆ = -4.0 mm Hg). Finally, a single SBP intragroup difference was found for the RE + SS protocol in Post-60 (p = 0.024; d = -3.12; ∆ = -5.0 mm Hg). Practitioners should be aware that SS and MM have the potential to influence BP responses in addition to RE or by themselves and therefore should be taken into consideration for persons who are hypertensive or hypotensive.

Beliefs, perceptions and practices of chiropractors and patients about mitigation strategies for benign adverse events after spinal manipulation therapy

BACKGROUND

Approximately 50% of patients who receive spinal manipulative therapy (SMT) experience some kind of adverse event (AE), typically benign and transient in nature. Regardless of their severity, mitigating benign AEs is important to improve patient experience and quality of care. The aim of this study was to identify beliefs, perceptions and practices of chiropractors and patients regarding benign AEs post-SMT and potential strategies to mitigate them.

METHODS

Clinicians and patients from two chiropractic teaching clinics were invited to respond to an 11-question survey exploring their beliefs, perceptions and practices regarding benign AEs post-SMT and strategies to mitigate them. Responses were analyzed using descriptive statistics.

RESULTS

A total of 39 clinicians (67% response rate) and 203 patients (82.9% response rate) completed the survey. Most clinicians (97%) believed benign AEs occur, and 82% reported their own patients have experienced one. For patients, 55% reported experiencing benign AEs post-SMT, with the most common symptoms being pain/soreness, headache and stiffness. While most clinicians (61.5%) reported trying a mitigation strategy with their patients, only 21.2% of patients perceived their clinicians had tried any mitigation strategy. Clinicians perceived that patient education is most likely to mitigate benign AEs, followed by soft tissue therapy and/or icing after SMT. Patients perceived stretching was most likely to mitigate benign AEs, followed by education and/or massage.

CONCLUSIONS

This is the first study comparing beliefs, perceptions and practices from clinicians and patients regarding benign AEs post-SMT and strategies to mitigate them. This study provides an important step towards identifying the best strategies to improve patient safety and improve quality of care.