Influence of Fatigue on Planned Agility Performance in Soccer Players.

International Journal of Exercise Science 13(1): 656-666, 2020. We investigated the acute fatiguing effects of sprint interval training (SIT) on change of direction performance in male and female soccer players. A T-test was performed once before (PRE) and twice following (POST 1 and POST 2) the completion of four sets of 4 s cycle ergometer sprints protocol. The sprint intervals were separated by 25 s active recovery. POST 1 was performed approximately 25 s following the final cycle sprint and POST 2 began two minutes after completing POST 1. Repeated measures ANOVA and Bonferroni post hoc tests were used to determine any significant differences in the time to complete the T-tests. The average power output drop measured during cycle SIT was 30.7 ± 9%. Time to complete the T-test significantly differed among the three tests (PRE: 10.46 ± .17 s; POST 1: 11.67 ± .33 s; POST 2: 10.96 ± .19 s; F (2, 54) = 6.174, p = .003). Post hoc test revealed an increase in time from PRE to POST 1 (p = .002) but no difference between PRE and POST 2 (p = .473). Nine participants (48%) were unable to complete POST 1 without errors; however, ten (52%) participants recovered enough to perform POST 1 without error. These results show that acute fatigue from SIT impairs change of direction performance, but performance can be recovered within a few minutes of rest. Coaches can combine fatigue inducing drills and change of direction training into same sessions with the right rest interval between the training modes

Contribution of the Ankle, Knee, and Hip to Total Lower Extremity Internal/External Rotation

The nature of the ankle, knee, and hip interaction can profoundly impact the movement patterns of the lower extremities. The ability to internally and externally rotate the lower extremity is essential in order to effectively absorb and apply force. In previous studies, most measurements have been conducted in 2D using a protractor, while mainly evaluating the hip. Dysfunction in any joint throughout the kinetic chain can lead to inefficient movement patterns that can compromise performance and potentially lead to injury. Appreciating the complexity of the lower extremity brings to attention the importance of any segments that are compromised. PURPOSE: To investigate the contribution of the ankle, knee, and hip to the total lower extremity internal rotation (IR) and external rotation (ER) range of motion (ROM) using a 3D camera system. METHODS: Fifteen college students participated in the study (21.2±1.9 years, 72.2±12.8 kg, 170.5±8.7 cm), eight males (21.1±1.2 years, 80.7±11.4 kg, 176.2±6.3 cm) and seven females (21.3±2.5 years, 62.5±5.0 kg, 163.8±6.0 cm). Lower extremity IR and ER ROM for each side were captured using 3D camera system, at 240 Hz. Each participant was instructed to perform maximal IR and ER in standing position, using sliding disk. Participants performed three trial of each rotation. Test-retest reliability identified good to excellent reliability, ICC 3,1 .797-.959. Based on this findings highest IR and ER ROM were further analyzed. Repeated measure ANOVAs were performed to determine differences between the three joints for each rotation and each side, followed by Bonferroni post-hoc analyses, were granted, pRESULTS: Significant main effect was found for IR of the right leg, p=.001 (hip 14.2o±5.5o, knee 12.0o±4.0o, and ankle 24.4o±9.9o). Post-hoc analyses revealed that ankle IR was significantly larger than hip IR (p=.022) and knee IR (p=.001). Significant main effect was found for IR of the left leg, p=.005 (hip 13.2o±3.4o, knee 12.2o± 5.6o, and ankle 23.6o±10.6o). Post-hoc analyses revealed that ankle IR was significantly larger than hip IR (p=.019) and knee IR (p=.003). Significant main effect was found for ER of the right leg, p=.001 (hip 17.1o±5.2o, knee 16.6o±3.1o, and ankle 26.8o±7.5o). Post-hoc analyses revealed that ankle ER was significantly larger than hip ER (p=.002) and knee ER (p=.001). No significant main effect was found for ER of the left leg, p=.138 (hip 18.7o±10.0o, knee 16.8o±5.9o, ankle 23.6o±7.3o). One-way ANOVAs Comparing between gender and side did not find any significant differences, p\u3e.05.CONCLUSION: The findings suggest that the ankle joint is contributing the most for IR and ER ROM. On average, ankle contributes 42%±9% to the lower extremity ROM during ER and 47%±13% during IR. The knee contributes 29%±9% to the lower extremity ROM during ER and 24%±8% during IR. The hip contributes 29%±10% to the lower extremity ROM during ER and 29%±12% during IR. Practitioners need to be caution when interpreting lower extremity or hip IR and ER ROM. Future studies need to further investigate the influence of each of the three joints IR and ER ROM on performance and injury

Case Presentation for Polycystic Ovarian Syndrome

CASE HISTORY: The patient is a fourteen-year-old female who presented to the clinic for bilateral hip and lumbar back pain. She stated that the pain has been present for approximately seven months and described it as a deep ache in the low back and both hips anteriorly. The patient said she plays a variety of sports but denies any specific event that could contribute to her pain. She stated her pain is worse with prolonged walking, standing, and sitting. Additionally, the patient mentioned her first menstrual cycle lasted fifty-six days and she has since not had any following menses, indicating secondary amenorrhea. Secondary amenorrhea is characterized by the cessation of irregular menses for six months and is commonly caused by hormonal imbalances. PHYSICAL EXAM: Examination of the hip, abdomen, and back did not demonstrate any deformities. She had tenderness to palpation at the mid-abdomen and at the insertion of the hip flexors, at the ASIS and AIIS bilaterally. Her patellar reflex was normal and 5/5 strength in hip flexion, extension, and abduction was observed along with full range of motion of both hips. FABER and FADIR tests were conducted and resulted in a positive sign of pain for both tests. DIFFERENTIAL DIAGNOSES: Hip dysplasia, Slipped capital femoral epiphysis, Polycystic Ovarian Syndrome, Femoroacetabular impingement, and Snapping hip. TESTS & RESULTS: Patient had an x-ray of both hips that were negative for tissue abnormalities. A pelvic MRI suggested small areas of sub-chondral sclerosis and possible polycystic ovaries. FINAL DIAGNOSIS: Polycystic Ovarian Syndrome (PCOS). DISCUSSION: PCOS is a common endocrine disorder that effects an estimated 10% of women between the ages of fifteen to forty-four, though it is commonly diagnosed in adolescence to early twenties. PCOS is diagnosed when two of the following criteria are evident: menstrual irregularity, polycystic ovaries and/or symptoms of androgen excess. Though pain is not an indicator of PCOS, it is not uncommon, and presentation varies widely to include abdominal, anterior pelvic, and low back pain. PCOS is believed to be caused by genetics but is greatly influenced by lifestyle factors and is associated with many morbidities including obesity, insulin resistance, and depression. Management of PCOS consists of controlling the symptoms of androgen excess and/or the absence of ovulation, and to reduce the chances of long-term complications such as infertility, metabolic syndrome, and type two diabetes. Oral contraceptives are the most common treatment for menstrual irregularity in adolescents. Androgen excess is managed with a combination of cosmetic management, oral contraceptives, and anti-androgen therapy, such as cyproterone acetate. Prevention of long-term complications include diet and lifestyle changes to reduce the risk of developing type two diabetes. Metformin may also be an effective treatment for both type two diabetes and androgen excess. OUTCOME OF THE CASE: Patient was referred to physical therapy to include protective range of motion and exercise of hip flexors. She continued to take Diclofenac for pain. RETURN TO ACTIVITY AND FURTHER FOLLOW-UP: The patient will follow-up with endocrinology and gynecologist for questionable polycystic ovarian syndrome due to polycystic ovaries present on the hip MRI and elevated testosterone levels. An x-ray without contrast of bilateral hips will be obtained to evaluate bony anatomy and she will return to the clinic in 4-6 weeks to follow-up on symptoms and discuss the imaging findings

The Effect of Scapular Dyskinesis on Upper Quarter Y-Balance Test Performance

The Upper Quarter Y-Balance Test (UQYBT) is a functional assessment tool that measures the stability and mobility of the upper extremity, while also analyzing symmetry. Scapular dyskinesis is defined as an alteration of the positioning and function of the scapula that impacts the overall kinetic chain, inhibiting proper shoulder movement. This condition is most prevalent in athletes participating in overhead sports such as swimming and tennis. Scapular dyskinesis decreases the range of motion of the shoulder resulting in a weakened performance. While it is unknown whether scapular dyskinesis is a cause or effect, it is believed that it increases the risk for shoulder injuries to occur. PURPOSE: to investigate if scapular dyskinesis impacts the performance on the UQYBT. METHODS: Twenty subjects (23±5 years; 76±17 kg; 173±10 cm), eight females and 12 males, participated in this study. Scapular dyskinesis was assessed using the Kibler Scapular Dyskinesis Test (SDT), on all subjects. Once the SDT was completed, the subjects performed the Upper Quarter Y-Balance Test (UQYBT). The three reach directions of the UQYBT are medial reach (MR), superolateral reach (SLR), and inferolateral reach (ILR). Three consecutive trials in all three directions were performed on the right and left arm, randomly. A one-minute resting period was given for each subject between trials. The best reach score for each direction and side was collected and normalized to the right upper extremity length. Composite scores were then calculated using the average of the three reach directions, for each side. One-way ANOVA analyses were used to compare the normalized reach scores for each direction, between the shoulders with scapular dyskinesis and the normal, p\u3c.05. RESULTS: Out of the 40 shoulders tested in this study, 15 shoulders were categorized as having scapular dyskinesis and the other 25 were categorized as normal. No significant differences were found when comparing all three normalized reach scores and normalized composite score between scapular dyskinesis shoulders and normal shoulders, p\u3e.05. For the normal shoulders, %MR was 98.4±7.9%, %SR was 73.1±13.5%, %IR was 81.1±12.8%, and %composite was 84.2±8.95%. In terms of the scapular dyskinesis shoulders, %MR was 95.6±8.9%, %SR was 69.9±13.9%, %IR was 83.8±12.6%, and %composite was 83.1±10.5%. CONCLUSION: In all three reach directions and composite scores, the scapular dyskinesis shoulders were observed to have similar results when compared to the normal shoulders. These results may indicate that subjects with scapular dyskinesis shoulders are able to achieve similar scores due to compensatory patterns of the muscles surrounding the shoulder girdle complex and thorax. Further research needs to be done to investigate if there are different compensatory mechanisms in individuals with scapular dyskinesis shoulders

Case Presentation for Lumbar Radiculopathy Consistent with Foraminal Stenosis and Herniated Nucleus Pulpous

CASE HISTORY: The patient was a 38-year-old male who presented with right lower extremity (LE) pain when performing lower back movements, with no specific low back pain. He stated that five months ago he felt an aching in his calves after performing a Romanian Deadlift, with shooting pain in his right lower extremity that radiated below the knee into the calf including paresthesia. The patient started a prednisone taper that helped relieve some of the symptoms, but after two weeks the symptoms resurfaced. The pain prevented him from exercising or performing certain ADLs. PHYSICAL EXAM: Examination of the right LE determined that reflexes at the patella and Achilles tendon are intact and strength remains present. Sensation decreased along the lateral right calf to the plantar surface of the right foot, but not along the lateral ankle or the foot dorsum. There was difference in sensation of plantar surface of the right and left sides. The straight leg raise test was negative. Increased tone of the quadratus lumborum on the right side was observed. Radiating pain down the right LE was reported while standing and extending the back. Forward flexion at the spine relieved the pain. DIFFERENTIAL DIAGNOSES: Disc bulge, low back pain, Lumbar radiculopathy, and Spondylolisthesis. TESTS & RESULTS: Patient had an MRI of the lumbar spine from the Anteroposterior (AP) and lateral view with flexion-extension. The AP view of the lumbar spine demonstrated no evidence of scoliosis, while the lateral view demonstrated a loss of lordosis that may be attributed to spasm of the back muscles. Further analysis showed that there appeared to be some degree of narrowing of the disc space at L5-S1, which is associated with facet joint disease extending from L3 to S1. FINAL DIAGNOSIS: L5 radiculopathy was consistent with L5-S1 foraminal stenosis on the right side with a disc protrusion. DISCUSSION: The prevalence of lumbar radiculopathy has been estimated to be about 3-5% of the population, affecting both males and females, with a male preponderance in the general population. Age is considered a primary risk factor, with symptoms typically beginning for males in their 40s, while females tend to be affected in their 50s and 60s. Current medical literature is at a consensus regarding the common causes of L5-S1 radiculopathy, intervertebral lumbar disc herniation. More than 90% of herniated discs occur at the L4-L5 or L5-S1 disc space. Compression of these spaces tend to produce a radiculopathy into the posterior leg and compromise or limit ADLs. Current guidelines suggest approaching lumbar radiculopathy in a conservative manner by educating patients, manual therapy, modifying exercises, staying active, and administration of a non-steroidal anti-inflammatory drug. OUTCOME OF THE CASE: Patient received one epidural steroid injection and is due for additional injection at L4-L5 or L5-S1. He was referred to physical therapy (PT) focusing on myofascial release and core stability exercises. Surgery was discussed but the patient stated that since he was improving, he would prefer to not proceed with surgical opinion at this time. RETURN TO ACTIVITY AND FURTHER FOLLOW-UP: Patient was instructed to perform his PT exercises along with light latissimus pull downs, chest supported back rows, and activities in the swimming pool. The patient will follow up over the next couple of weeks on his status post epidural steroid injection. Regarding disability, it has been determined that he will decide when he is ready to return to full administrative abilities. After his follow up, a program structured around his abilities for recovery and/or future need will be discussed

Gender Performance Differences in Standard Upper Quarter Y-Balance Test and Two Modified Versions

Preparticipation screening evaluating musculoskeletal functioning is gaining popularity in young adults. The Upper Quarter Y-Balance Test (UQYBT) is often used to measure shoulder mobility and stability, and screening for upper extremities musculoskeletal injuries. The UQYBT is renowned for its unique approach to testing shoulder and core stability in the athletic and active population. Its feasibility in less active individuals is questionable due to its strength and balance requirements. Moreover, there is minimal data comparing UQYBT scores between genders of different fitness levels. PURPOSE: To examine performance differences between women and men executing the standard UQYBT and two modifications. METHODS: Eleven women (22.5±3.2 years, 1.64±0.04 m, 66.1±10.5 kg) and nine men (27.0±8.8 years, 1.74±0.03 m, 74.2±12.8 kg) college students took part in this study. Prior to testing, participants completed five minutes warm-up on an arm ergometer. Participants completed the three UQYBT variations in a randomized order; Standard (traditional push-up position), Modified (modified push-up position), and Wall (standing erect). In each variation, participants completed three reaches in the medial, inferolateral, and superolateral direction. Maximal relative scores were collected, and composite scores were calculated. MANOVA was conducted comparing the differences between women and men reach scores in each direction and for each UQYBT variation. Significance level was set to .05. RESULTS: Significant differences were observed in the Modified UQYBT for the inferolateral reach, women had higher max relative scores than men, p-value\u3c.01. Women average maximal relative score was 89±10%, whereas men average score was 80±8%. Similar significance trend was identified in the Wall UQYBT during the inferolateral reach. Women reach score (82±8%) was higher than the men reach score (72±11%), p-values\u3c.01. No significant differences were observed in any of the other reaches measured during the three UQYBT variations. CONCLUSION: In this study we measured gender differences during three UQYBT variations. The most body weight the upper extremity needs to balance is during the Standard position, followed by the Modified and Wall UQYBT. We have found gender differences in the Modified and Wall UQYBTs during the inferolateral reach. The difference may be related to fact that during the Modified and Wall UQYBTs there is less body weight on the upper extremity which may increase women ability to have better shoulder mobility and stability than the men. Further research is required in this area

Case Presentation for Suprascapular Neuropathy

CASE HISTORY: The patient is an 18-year-old female collegiate volleyball player who has suffered progressive shoulder pain in her right shoulder. She states that the pain has progressively gotten worse over the past 3-4 years. The sharp pain began when she would raise her right arm above 90 degrees when hitting an overhand serve. Over time, the pain progressed and became noticeable in additional movements. The patient had noted significant weakness in both her right arm and right shoulder. The patient states when she sleeps on her right arm/shoulder she wakes up in severe pain. She has tried sleeping with the right elbow in extension which has helped in alleviating the pain. PHYSICAL EXAM: The patient’s vital signs were all within normal ranges. A physical exam was performed and identified pain with Hawkins-Kennedy and empty can. Manual muscle testing demonstrated infraspinatus (2/5) and supraspinatus (3/5) weakness. Upper Quarter Y Balance Test revealed right and left composite scores of 85.7 and 96.1, respectively. DIFFERENTIAL DIAGNOSES: Suprascapular nerve palsy; Ulnar nerve palsy; Infraspinatus atrophy; Subacromial impingement syndrome; and rotator cuff injury. TESTS & RESULTS: An X-ray for the right arm and shoulder was also preformed which did not show any pathologies. The patient had a magnetic resonance imaging (MRI) of the right arm and shoulder revealing two lesions in the head of the humerus. An MRI of the cervical spine without contrast was preformed and revealed a mild disk bulge at C5 and C6 with no significant Neural Foraminal Stenosis (NF) narrowing. There was straightening and very slight reversal of the normal cervical lordosis. A nerve conduction study was performed and identified a right sided suprascapular neuropathy at the spinoglenoid notch with significant motor axon loss. Lastly, electrophysiologic testing was done which identified right sided ulnar neuropathy. FINAL DIAGNOSIS: Right sided suprascapular neuropathy at the spinoglenoid notch. Right sided ulnar neuropathy. DISCUSSION: Suprascapular neuropathy is a very uncommon cause for shoulder pain and is often times misdiagnosed. Frequently the diagnosis of suprascapular neuropathy is mistaken for subacromial impingement syndrome, rotator cuff injuries, etc. Common signs and symptoms of suprascapular neuropathy are pain and weakness in the shoulder, atrophy, and often burning and aching. Suprascapular neuropathy is reported to only be found in 0.4% of patients with shoulder pain. The compression of the suprascapular nerve at the spinoglenoid notch is often due to repetitive use and space-occupying lesions. Athletes that perform sports like tennis, weight-lifting, and volleyball are more likely to experience a suprascapular neuropathy injury. OUTCOME OF THE CASE: The patient has been diagnosed with suprascapular neuropathy caused by compression of the suprascapular nerve at the spinoglenoid notch. This patient has been prescribed a rehabilitation program involving the throwers ten to strengthen her rotator cuff muscles along with improving her scapular and glenohumeral stabilization and proprioception. The athlete is participating in normal practice and play and has been told to take over the counter anti-inflammatory medications such as ibuprofen, as needed. RETURN TO ACTIVITY AND FURTHER FOLLOW-UP: The patient is to remain in normal practice and play and continue her basic rehabilitation program. She has been referred to a surgical doctor and has been asked to seek a surgical consultation in the future

The Influence of Hip Position on Lower Extremity Internal/External Rotations and Its Reliability

The hip joint is important in activities of daily living (ADL), allowing tri-planar movements simultaneously. Range of motion (ROM) of the hips is essential for ADL, where a decreased hip ROM is associated with higher lower extremity injuries. Measuring ROM of the hips can assist in preventing lower extremity injuries. Goniometry is a common method used in measuring passive and dynamic hip ROM, however, limited mainly to non-weight bearing positions such as supine, prone and sitting. PURPOSE: To investigate the influence of weight bearing hip position on lower extremity internal rotation (IR) and external rotation (ER) ROM and its reliability, in the general population. METHODS: Ten participants (six males and four females, 21.9+2.4 years) participated in the study. The participants performed lower extremity IR and ER in eight randomized hip positions, on a rotational disc device with 360 dial (one-degree accuracy). The following are the eight hip positions: flexion IR (FIR), flexion ER (FER), extension IR (EIR), extension ER (EER), abduction IR (ABDIR), abduction ER (ABDER), adduction IR (ADDIR), and adduction ER (ADDER). Participants maximum IR and ER ROM was recorded using a video camera and measured in each hip position, by two raters. Participants were cued to hold the end ROM for 2 s. Each position was repeated three times for both right and left sides. A test-retest analyses were performed between the three consecutive trials in all eight hip positions, for each rater. Interrater analyses were performed between the two raters. Repeated measure ANOVAs were performed to determine the influence of different hip positions on hip IR and ER ROM, followed by Bonferroni post-hoc analyses, were granted, p\u3c.05. RESULTS: Test-retest reliability for each hip position, side, and rater were between good to excellent, ICC 3,1 .802-.945. Based on the high reliability for each rater, the third trial was chosen to run the interrater analyses. Interrater reliability for each hip position and side were between very good to excellent, ICC 3,1 .876-.997. Repeated measure ANOVAs found significant main effects in hip IR (p\u3c.001) and ER (p=.025). Bonferroni post-hoc analyses found the following: FIR (43.4±10.7) was significantly larger than EIR (31.4±8.4), p=.001; ABIR (41.2±10.3) was significantly larger than EIR, p=.003; ADIR (44.7±13.0) was significantly larger than EIR, p\u3c.001; and FER (52.5±15.0) was significantly larger than ADER (44.9±15.4), p=.011. CONCLUSION: This study found good to excellent reliabilities for the test-retest analyses and very good to excellent reliability for the interrater reliability. Furthermore, Hip starting position found to influence mainly the IR ROM. When the hip was in flexion position IR and ER ROM were the largest. Practitioners need to be aware that measuring lower extremity IR and ER ROM in different weight bearing hip starting positions may influence the measurement outcome. These findings provide important information to consider when developing injury prevention programs and rehabilitation testing protocols

The Early Propagation And Burning Of Hydrogen In The Process Of The Deflagration To Detonation Transition

The safe and efficient propagation of the Deflagration to Detonation Transition (DDT) is a topic that has been researched for many years due to its applications in Aerospace and Mechanical Engineering. DDT is when fire caused by the burning of fuel is accelerated to the upper CJ point on the Rankine Hugoniot curve due to instabilities in the flame and the turbulence caused by these instabilities. The complex flame dynamics that go along with DDT have ensured that the process is yet to be fully understood and defined. This research will work towards observing the early stages of burning hydrogen-air mixtures in DDT conditions in order to better understand the processes that cause DDT. The research will also involve the testing of multiple different equivalence ratios of hydrogen known to undergo DDT. This research will assist in making places that store reactive gasses such as hydrogen safer by searching for the method of DDT formation and ways to prevent it. This research will also allow for safer commercial use of DDT in Detonation Based Engines. The research was tested in a secure facility and observed the first four inches of ignition and deflagration using schlieren and chemiluminescence imaging techniques. Through the research, it was found that flames at higher equivalence ratios tend to be longer, more top-biased, and have more instabilities than flames of lower equivalence ratios, better preparing them for DDT. This study will be elaborated on in future research using a variety of different fuels to solidify the findings of the research performed and to assist in the ability to innovate using DDT

Lack of Correlation Between Natural Pelvic Tilt Angle with Hip Range of Motion, and Hip Muscle Torque Ratio

International Journal of Exercise Science 14(1): 594-605, 2021. Excessive anterior and posterior pelvic tilts (PT) angles are associated with overuse injuries of the lower limbs and of the lumbo-pelvic-hip complex. There is a lack of evidence that correlates anterior and posterior PT angles with limited hip internal rotation (IR) and external rotation (ER), and hip muscles torque ratios. The purpose of this study was to examine the correlation between averaged anterior/posterior PT angle in standing position and hip IR and ER range of motion (ROM), hip adductors and abductors (Add/Abd) torque ratio, and hip flexors and extensors (Flexor/Extensor) torque ratio. Twenty-six healthy participants participated in this study, fifteen females (22.0 ± 2.8 yrs, 163.5 ± 7.5 cm, 65.9 ± 10.4 kg) and eleven males (22.0 ± 2.2 yrs, 178.5 ± 4.5 cm, 78.4 ± 8.7 kg). Hip muscle torques were collected with an isokinetic dynamometer, five trials at 30 degrees per second (deg· s-1) and at 60 deg· s-1. The measurement of PT in standing natural position and hip IR and ER ROM in functional weight-bearing lunge position were recorded, using a 3D Motion Analysis System. There were no significant correlations between PT angle and hip IR and ER (p ≥ 0.05), no significant correlations between PT angle and hip Add/Abd torque ratio (p \u3e 0.05), and no significant correlations between PT angle and hip Flexor/Extensor torque ratio (p \u3e 0.05). The measurement of PT angle in standing natural position was not associated with hip IR and ER ROM and hip Add/Abd and Flexor/Extensor torque ratios, in healthy population