Vascular Alteration with Postural Change as Observed Using the Anterior Tibial Artery: A Pilot Study

Plantar fasciopathy and plantar fasciosis are common lower extremity conditions. Vascular health is an important aspect of plantar fascia health. Footwear choices are thought to influence lower extremity vascular flow, but how the anterior tibial artery is affected by purely postural changes over time is unknown. PURPOSE: To observe the anterior tibial artery vascular alterations over a ten-minute period after transitioning from a sitting to a standing position while barefoot. METHODS: Nine participants (age= 23.8yrs ±2.5, height= 176.0cm ±8.0, weight= 69.8kg ±10.2) were recruited from Brigham Young University for a single 30-minute visit. The participants had no previous lower extremity injuries within 6 months. The individual’s dominant foot arch height index was recorded, and the participant had a 3-lead ECG placed on their trunk. A Logic Fortis machine with an L8-18i probe was used to capture pulse wave (PW) images of the anterior tibial artery of the dominant foot. The participant sat barefoot on an elevated platform for five minutes and baseline PW was recorded. The participant then stood on the platform for 11 total minutes. PW images were captured once at the end of every minute for the first five minutes and a final PW measurement was captured after ten minutes of standing. A paired t-test was used to compare standing time points to baseline (α=0.05). RESULTS: After standing, time-averaged mean velocity (TAMean) significantly dropped through minutes one (pCONCLUSION: Blood flow through the anterior tibial artery is significantly altered with postural changes likely through cardiovascular responses. Vascular recovery is observed after three minutes while the average increase in vascular response occurs around ten minutes

Differences in Arterial Occlusion Pressure of the Superficial Femoral Artery Between the Dominant and Non-Dominant Legs

The arterial occlusion pressure (AOP) is dependent on limb circumference. Previous research seldom reports the AOP of both limbs. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP measured in the dominant and non-dominant legs. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in a random order in 20 males and 20 females. Circumference of the upper thigh, leg volume, and skinfold thickness were measured in both legs. Blood pressure was continuously monitored using a CNAP device. An inflatable cuff was placed around the upper thigh. The cuff was inflated to 50 mmHg and then inflated continuously (10 mmHg/10 s) until arterial blood flow and pulse waves were no longer detectable by the ultrasound. The AOP was then measured in the opposite leg. The AOP data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: In males, the AOP of the dominant (209.4 ± 29.4 mmHg) and non-dominant legs (206.8 ± 32.5 mmHg) were not significantly different (p=0.790). Likewise, in females the AOP of the dominant (212.3 ± 58.3 mmHg) and non-dominant legs (203.5 ± 50.9 mmHg) were not significantly different (p=0.386). When combining the data for males and females, the AOP of the dominant (210.9 ± 45.6 mmHg) and non-dominant legs (205.2 ± 40.7 mmHg) were not significantly different (p=0.412). Thigh circumference was the only variable that significantly (p=0.027) contributed to AOP. In both males and females, there were no differences in thigh skinfold thickness, circumference, and volume between the dominant and non-dominant legs. The dominant leg was larger in 24 (60%) of the subjects; the larger leg had a higher AOP in 19 (47.5%) of the subjects; and the dominant leg had a higher AOP in 26 (65%) of the subjects. Although the AOP between the dominant and nondominant legs was not statistically significant, the largest difference in AOP between the two legs was 124 mmHg. CONCLUSION: There were no significant differences in AOP of the superficial femoral artery between the dominant and non-dominant legs in either males or females. Because of the potentially larger differences in the AOP between the two legs, we recommend measuring the AOP in both limbs when using blood flow restriction during exercise

Sex Differences in the Superficial Femoral Artery Occlusion Pressure

The measurement of arterial occlusion pressure (AOP) prior to the use of blood flow restriction during exercise is recommended. Not all previous studies that have included both male and female participants have reported sex differences in AOP. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP of the dominant and non-dominant legs between males and females. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in a random order in 20 males and 20 females. Circumference of the upper thigh, leg volume, and skinfold thickness were measured in both legs. Blood pressure was continuously monitored using a CNAP device. An inflatable cuff was placed around the upper thigh. The cuff was inflated to 50 mmHg and then inflated continuously (10 mmHg/10 s) until arterial blood flow and pulse waves were no longer detectable by the ultrasound. The AOP was then measured in the opposite leg. The AOP data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: The AOP of the dominant leg in males (209.4 ± 29.4 mmHg) and females (212.3 ± 8.3 mmHg) were not significantly different (p=0.844). Likewise, the AOP of the non-dominant leg in males (206.8 ± 32.5 mmHg) was not significantly different (p=0.804) than the AOP in the non-dominant legs of females (203.5 ± 50.9 mmHg). When combining the data for the dominant and non-dominant legs, the average AOP for males (208.1 ± 30.6 mmHg) and females (207.9 ± 53.1 mmHg) were not significantly different (p=0.986). Thigh circumference was the only variable that significantly (p=0.027) contributed to AOP. On the average the thigh circumference in the dominant and non-dominant legs of males (59.6 ± 5.5; 59.2 ± 5.2 cm) was greater than that for females (56.0 ± 2.9; 55.6 ± 3.2 cm), respectively. There were no sex differences in thigh skinfold thickness or thigh volume between males and females in either the dominant or non-dominant legs. CONCLUSION: There were no significant differences in AOP of the superficial femoral artery of the dominant and non-dominant legs between males females despite males having larger legs. Factors other than limb circumference likely have a role in determining AOP

Differences in Arterial Occlusion Pressure Using Two Different Cuff Inflation Protocols

The occlusion pressure used during blood flow restriction during exercise is based on the arterial occlusion pressure (AOP). Although previous studies have measured AOP using two different cuff inflation protocols, no studies have compared the AOP measured using both protocols. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP when measured using two different cuff inflation protocols. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in 20 males and 20 females. An inflatable cuff was placed on the upper thigh. The superficial femoral artery was occluded using two different cuff inflation protocols in a random order in both legs. The continuous (CONT) protocol involved inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s until blood flow could no longer be detected using the ultrasound. The incremental (INCR) protocol involved inflating the cuff to 50 mmHg for 30 s, and then deflating the cuff for 10 s. The cuff was then inflated incrementally with each subsequent inflation increasing by 30 mmHg for 30 s followed by deflating the cuff for 10 s. Once blood flow was occluded, cuff pressure was decreased in increments of 10 mmHg until there was evidence of blood flow. The cuff was then gradually inflated until blood flow was no longer detected. RESULTS: In males, the AOP measured in the dominant (209.4 ± 29.4; 208.2 ± 27.1) and non-dominant (206.8 ± 32.5; 206.2 ± 32.7) legs using the CONT and INCR cuff inflation protocols, respectively, were not significantly different (p\u3e0.05). Likewise, in females the AOP measured in the dominant (212.3 ± 58.3; 213.7 ± 53.9) and non-dominant (203.5 ± 50.9; 207.0 ± 50.2) legs using the CONT and INCR protocol, respectively, were not significantly different (p\u3e0.05). When combining male and female data, there were no significant differences in the AOP between the CONT and INCR cuff inflation protocols in either leg or when combining legs. CONCLUSION: Using a continuous or incremental protocol for occluding the superficial femoral artery resulted in similar AOP values. Either protocol can be used in future research as well as in settings where AOP is determined prior to the use of blood flow restriction during exercise

Differences in Arterial Occlusion Pressure as Measured using Ultrasound and a Hand-Held Doppler Device

In the research lab and clinical settings, expensive ultrasound machines are used to measure arterial occlusion pressure (AOP) prior to the use of blood flow restriction during exercise. Alternatively, inexpensive hand-held Doppler ultrasound devices may be used to measure AOP in various applications and settings. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP as measured using ultrasound and a hand-held Doppler device. METHODS: Participants included 20 males and 20 females. An inflatable cuff was placed on the upper thigh. The superficial femoral artery was occluded by inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s. A GE LOGIQ ultrasound was used to detect blood flow in the superficial femoral artery just below the cuff. A hand-held Doppler device was used simultaneously to detect blood flow (pulse waves) at the anterior medial malleolar artery of the ankle. The pressure at which blood flow could no longer be detected using the ultrasound and the hand-held Doppler were recorded as the AOP. The measurement of AOP using both devices simultaneously was performed on both legs in a random order. The data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: On the average, the AOP measured using the hand-held Doppler device was significantly (pCONCLUSION:Although the differences in the AOP measured using the Ultrasound and the hand-held Doppler in both legs in males and females was statistically significant, for all practical purposes, the small differences were of not practical importance. In settings in which blood flow restriction during exercise is employed, a hand-held Doppler device is a viable alternative to using expensive ultrasound machines to measure AOP

Comparative Investigation of Foot Blood Flow Dynamics: A Study of the Anterior and Posterior Tibial Arteries in the Sitting vs. Standing Positions

Optimal blood circulation is crucial to perform activities of daily living and for living a healthy life. For example, insufficient blood flow to the foot contributes to the development of foot pathology such as plantar fasciopathy. An unshod simulation of tight and narrow shoes showed decrease blood flow to the foot. PURPOSE: This study investigated if there was a significant decrease in blood flow to the foot via the anterior and posterior tibial arteries when an unshod person transitions from sitting to standing. METHODS: Nine individuals participated in this pilot study (age=24.7±4.4, weight=72.7kg±8.8, height=1.8m±0.07). For the sitting position, participants sat on a platform while blood flow volume measurements were taken simultaneously of the anterior and posterior tibial arteries using ultrasound pulse wave. For the standing measurements, the participants stood on the platform and the same measurements were taken. A period of three minutes after standing was implemented before standing measurements were taken to ensure that blood flow adjusted to the new position. A paired t-test was used to compare sitting to standing differences within the participants. RESULTS: In the anterior tibial artery, average volume flow changed from 4.88 ml/min (sitting) to 2.76 ml/min (standing), a 43.4% drop in blood flow (p\u3c0.01). In the posterior tibial artery, volume flow decreased from an average of 5.01 ml/min to 3.69 ml/min, a decrease of 26.3% (p\u3c0.05). Total reduced blood flow between the two arteries decreased from 9.89 ml/min to 4.88 ml/min, a 50.6% drop (p\u3c0.01). CONCLUSION: This study demonstrates a simple change in position significantly impacts blood flow to the foot. This suggests further research is needed to determine if there is an additive effect of footwear on this observed decrease in blood flow that may contribute to an increase incidence rate of plantar fasciopathy. This finding additionally provides rationale to investigate what mechanism the body uses to overcome positional-related decreases in blood flow

Reliability of Arterial Occlusion Pressure Measurements Using Two Different Cuff Inflation Protocols

Although previous studies have used two different cuff inflation protocols to measure AOP, no studies have reported the reliability of AOP measurements using both protocols. PURPOSE: The purpose of this study was to evaluate the reliability of two measurements of AOP in the superficial femoral artery using two different cuff inflation protocols. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in 20 males and 20 females. The AOP of the artery was measured twice in each leg. The artery was occluded using a continuous (CONT) cuff inflation protocol in one leg and an increment (INCR) cuff inflation protocol in the opposite leg. The CONT protocol involved inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s until blood flow could no longer be detected using the ultrasound. The INCR protocol involved initially inflating the cuff to 50 mmHg for 30 s, and then deflating the cuff for 10 s. The cuff was then inflated incrementally with each subsequent inflation increasing by 30 mmHg for 30 s followed by deflating the cuff for 10 s. Once blood flow was occluded, cuff pressure was decreased in increments of 10 mmHg until there was evidence of blood flow. The cuff was then gradually inflated until blood flow was no longer detected. The pressure at which blood flow could no longer be detected was recorded as the AOP. The data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: The difference in the two measurements of AOP using the CONT and INCR cuff inflation protocols in males (0.9 ± 5.4 and 0.5 ± 5.1 mmHg) and females (1.9 ± 11.4 and 2.3 ± 12.2 mmHg), or when combining the data from males and females (0.4 ± 8.9 and 0.9 ± 9.3 mmHg), respectively, were not statistically significant. The correlations between the two measurements of AOP using the CONT and INCR cuff inflation protocols all exceeded 0.99. CONCLUSION: Measurements of AOP using a continuous or increment cuff inflation protocol are highly reliable. Either cuff inflation protocol can be used when making multiple measurements of AOP

Measuring Brachial Artery Occlusion Pressure Using a Hand-held Doppler and Pulse Oximeter

The measurement of arterial occlusion pressure (AOP) is recommended for the safe and effective use of blood flow restriction (BFR) during training. PURPOSE: This study compared measurements of brachial artery AOP using Doppler ultrasound (US), a hand-held Doppler (HHDOP) and a pulse oximeter (PO). METHODS: The AOP of the brachial artery was measured simultaneously using US, HHDOP, and a PO in the dominant arm of males (n=36) and females (n=49). The blood flow restriction cuff was inflated using a continuous cuff inflation protocol. RESULTS: A mixed model ANOVA revealed small but significant (p \u3c 0.05) overall main effects (combined males and females) between AOP measured using US (119.8 ± 13.2 mmHg), HHDOP (119.1 ± 13.1 mmHg) and PO (118.0 ±13.2 mmHg), and between males (125.3 ± 13.1 mmHg) and females (114.3 ± 11.1 mmHg). The differences in AOP between males and females was consistent across all three methods of measuring AOP (US, HHDP, PO) and may be attributed to sex differences in limb circumference and systolic blood pressure. The small overall difference between US and HHDOP (0.74 ± 2.7 mmHg) was not significant but the difference between US and PO (1.81 ± 3.3 mmHg) measures of AOP was significant (

Individuals Wearing Cleats Transitioning from Sitting to Standing Demonstrate a Significant Decrease in Blood Flow to the Foot

Plantar fasciopathy is a common foot condition with 10% prevalence in the general population. Plantar fasciosis (a type of fasciopathy) is considered a degenerative condition associated with cell death due to a lack of blood flow. Narrow, tight footwear, such as cleats, have been implicated as a potential contributing factors for the development of plantar fasciopathy and their direct influence on blood flow to the foot is currently unknown. PURPOSE: To investigate blood flow change in the anterior and posterior tibial arteries between sitting and standing in a cleated foot. METHODS: Eight individuals participated in this pilot study (weight=70.5 kg±12.9, height=1.8m±0.17). The participant put cleats on both feet, with a perceived tightness of 5/10 or greater on a VAS scale. Blood flow volume measurements of the anterior and posterior tibial arteries were taken simultaneously using pulse wave ultrasound, while the participant sat on a platform. These measurements were then repeated in the standing position on the same platform. Blood flow was measured in the dominate shod foot. A paired t-test was used to compare sitting to standing conditions within participants. RESULTS: In the anterior tibial artery, average volume flow changed from 6.25 ml/min (sitting) to 2.6 ml/min (standing), a 58% drop in blood flow (p=0.09). In the posterior tibial artery, volume flow decreased from an average of 11.25 ml/min to 3.95 ml/min, a decrease of 65% (p\u3c0.05). Total reduced blood flow between the two arteries decreased from 8.75 ml/min to 3.28 ml/min, a 63% drop (p\u3c0.05). CONCLUSION: There appears to be an important alteration of blood flow to the foot in individuals wearing cleats as they transition from a sitting to standing position. If this decrease in blood flow were to persist while wearing cleats, it may help explain the development of plantar fasciopathy observed in individuals wearing narrow, tight footwear