The FAIR test is a sensitive and specific test for detection if irritation of the sciatic nerve by the piriformis. FAIR stands for flexion, adduction and internal rotation. Also known as piriformis test.
Clinically Relevant Anatomy[edit | edit source]
The piriformis is a flat muscle and the most superficial muscle of the deep gluteal muscles. It is part of the lateral rotators of the hip [obturator internus, superior and inferior gemelli, quadratus femoris, obturator externus, and gluteus maximus]. It leaves the pelvis through the greater sciatic notch, until its fixation reaches the superior margin of the greater trochanter[1]. It has a piramidal shape that lies almost parallel with the posterior margin of the gluteus medius.[2]
The piriformis muscle can be used to locate the scietic nerve. This nerve enters the gluteal region inferiorly to the piriformis.If the lateral rotators of the hip are tight they may exert pressure on the sciatic nerve, producing pain radiating into the lower extremity[1][3].This is known as Piriformis Syndrome.
For more detailed information on the anatomy of the piriformis muscle.
Background[edit | edit source]
Number of extremities studied, 1510 [4]
A: Usual relationships with the sciatic nerve passing from the pelvis beneath m. piriformis.
B: M. piriformis divided into two parts with the peroneal division of the sciatic nerve passing between the two parts of piriformis.
C: The peroneal division of the sciatic nerve passes over m. piriformis and the tibial division passes beneath the undivided muscle.
D: In these cases, the entire nerve passes through the divided m. piriformis.
Technique[edit | edit source]
Position the patient in the side-lying with the tested hip on top. Passively move the patient's lower extremity into flexion [90 degrees], adduction, and internal rotation. The examiner stabilizes the hip and applies downward pressure to the knee to internally rotate and adduct the hip,[5] [6] thus placing the piriformis on a stretch that compresses the sciatic nerve. A positive test occurs when pain is produced in the sciatic/gluteal area. Due to the position of the test, pain may produced in the anterior thigh as well as a result of femoral acetabular impingement, so it is important to ask where they are feeling the pain.
Variation[edit | edit source]
The FAIR test can be performed with the patient supine or seated, knee and hip flexed, and hip medially rotated, while the patient resists examiner attempts to externally rotate and abduct the hip.
The FAIR test result is positive if sciatic symptoms are recreated. [7][8][9][10][11]
Interpretation[edit | edit source]
Sciatic nerve pain can originate from several factors which include; a disc herniation, sacroiliac joint dysfunction, degenerative joint disease, a tight piriformis, and more. If you suspecting a patient's neural symptoms to be originating from tightness of the piriformis muscle, the FAIR test may be used to help strengthen your hypothesis. According to Neumann, the piriformis originates at the ventral surface of the sacrum and runs through the greater sciatic foramen to insert on the superior part of the greater trochanter, leading to the actions of hip external rotation, abduction, potentially slight extension [due to the posterior to anterior line of pull][12]. The position of flexion, adduction, and internal rotation places a stretch on the piriformis muscle and, theoritically, compressing the sciatic nerve. Additionally, a ROM assessment, palpation skills, and movement analysis would be very beneficial in your physical examination to help confirm your hypothesis.
Evidence Based[edit | edit source]
The FAIR test correlates well with a working definition of piriformis syndrome, based on prolongation of the H-reflex with hip flexion, adduction, and internal rotation [FAIR] and is a better predictor of successful physical therapy and surgery than the working definition. The FAIR test, coupled with injection and physical therapy and/or surgery, appears to be effective means to diagnose and treat piriformis syndrome. [11]
Diagnostic accuracy has been reported as; Sensitivity: .88; Specificity: .83; +LR: 5.2; -LR: .14 [11]
["Piriformis syndrome: Diagnosis, treatment and outcome- a 10-year study," "Unilateral limitation of abduction of the hip: A valuable clinical sign for DDH?"].[13]
- ↑ 1.0 1.1 Oatis, C. A., [2009]. Kinesiology : the mechanics and pathomechanics of human movement [2nd ed]. Baltimore : Lippincott Williams & Wilkins.
- ↑ Piriformis. [2017, June 6]. Physiopedia, . Retrieved 09:52, December 15, 2017 from //www.physio-pedia.com/index.php?title=Piriformis&oldid=174010.
- ↑ //teachmeanatomy.info/lower-limb/muscles/gluteal-region/
- ↑ From Beaton, L.E. and B.J. Anson. The relation of the sciatic nerve and its subdivisions to the piriformis muscle. Anat. Rec. 70:1-5, 1938
- ↑ Kirschner JS, Foye PM, Cole JL. Piriformis syndrome, diagnosis and treatment. Muscle Nerve Jul 2009 ; 40[1] : 10-18
- ↑ Lori A, Boyajian- O’ Neill et al. Diagnosis and Management of Piriformis syndrome : an osteopathic approach. The journal of the American and osteopathic association Nov 2008; 108[11]: 657-664.
- ↑ Pace JB, Nagle D. Piriformis syndrome. West J Med. 1976; 124: 435-439.
- ↑ Foster MR. Piriformis syndrome. Orthopedics. 2002; 25: 821-825
- ↑ Benzon HT, Katz JA, Benzon HA, Iqbal MS. Piriformis syndrome: anatomic considerations, a new injection technique and a review of the literature. Anesthesiology. 2003; 98: 1442-1448.
- ↑ Magee DJ. Orthopedic physical assessment. 3rd ed. Philadelphia. Pa: WB Saunders Co; 1997
- ↑ 11.0 11.1 11.2 Fishman LM, Dombi GW, Michaelsen C, Ringel S, Rozbruch J, Rosner B, et al. Piriformis syndrome: diagnosis, treatment and outcome- a 10 year study [review] Arch Phys Med Rehabil. 2002; 83: 295-301.
- ↑ Neumann, Donald. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 2nd edition. St. Louis, MO: Mosby Elsevier, 2010. 498. Print.
- ↑ Jari S, Paton RW, Srinivasan MS. "Unilateral limitation of abduction of the hip: A valuable clinical sign for DDH?" J Bone Joint Surg2002; 84-B: 104-107. Web. 08/25/2012.
Activity 1: A Survey about Science
Now is your chance to find out what your friends and family members think about science. You will share information with your classmates to create a picture of your community's knowledge about and comfort level with science. By the end of this lesson, you will have a better understanding of what science is and isn't. This will form a strong basis for your study of evolution.
Procedures
1. Print the Science Survey form [pdf], or use the form distributed by your teacher. Answer the questions without using reference materials.
2. Discuss and review your answers with your teacher before you conduct the survey with other people.
3. Now conduct the survey in your community to find out what your friends, family, and neighbors think about science and scientists.
4. Ask at least five different people the questions in the survey. You need to get a variety of opinions, so choose people from different age groups and backgrounds [school friends, parents, relatives, neighbors, and teachers]. Your teacher may assign the groups you are to survey.
5. Be prepared to discuss the following questions in class.
- Describe the individuals sampled. How many participants were students? How many were adults? How many work in a science-related field?
- How many people gave an accurate definition of science?
- How many said they liked science?
- How many had misconceptions about what a theory, a fact, or a law is?
- How many people gave a scientific definition of evolution?
- How many knew the difference between astrology and astronomy? Why is this significant in a discussion about the nature of science?
- What misconceptions about science did you encounter in your survey results?
Activity 1 Teacher Notes: A Survey about Science
This is a survey students will conduct about the nature of science, laws, theories, hypotheses, scientists, and evolution. They will first take the survey themselves and then, after an in-depth classroom discussion, conduct the survey in their community.
Learning Goals
- To have students explore the public's perception of science and the scientific process
- To foster an awareness that the public often has a very different perception of these terms and concepts than the scientific community
- To have students explore and discuss the implications of scientific literacy
1. Have your students complete the Science Survey form [pdf].
2. Then, discuss the concepts covered in the survey [scientific process, theory, fact, law, and evolution].
3. Discuss with your class what it means to "like" science. Discuss the difference between thinking of science as a subject in school and thinking of it as a way to understand the world.
4. Ask students what they think the difference is between astronomy and astrology. Explore how this is related to the nature of science.
5. Have students conduct the survey with at least five people. You may want to assign the age or status [parents, teachers, friends] of those to be surveyed to ensure a broad sample.
6. Have students tally the results for the following questions on the board:
- How many survey participants were students? How many were adults? How many work in a science-related field?
- How many people gave an accurate definition of science?
- How many said they liked science?
- How many had misconceptions about what a theory, a fact, or a law is [as used in the scientific community]?
- How many people gave a scientific definition of evolution?
- How many people knew the difference between astronomy and astrology?
- Find the total number of people surveyed. Then calculate percentages for each question above. If you teach more than one class, you can compare data between classes. You may want to discuss how factors like sample size or bias in selection of participants affect the statistical significance of your results. Students might want to examine how responses varied by age group or gender or look for correlations between questions by a single respondent. For instance, were those who gave accurate definitions for the term science more likely to say they like it?
7. Ask students to contribute some of the definitions they collected for the term evolution. As a class, revise five of the definitions so they are correct.
8. Ask students to correct the definitions that their survey participants gave for the terms science, evolution, theory, fact, and law. This exercise will help them develop critical thinking skills. Not only will they be able to define the terms, but they will be able to recognize when they are used incorrectly. After this exercise, discuss why evolution is called a theory.
9. Wrap up this activity by asking students to explore ways to address misunderstandings they uncovered while conducting the survey. Ask students to consider the importance of scientific literacy in the 21st century, a time when science influences every aspect of our lives from shopping at the grocery store [genetically modified food], to choosing a car [environmental implications], to voting on political issues [ecology, health, conservation, and technology].
Activity 2: What Killed the Dinosaurs?
One of the great, unsolved mysteries in science is the disappearance of the dinosaurs. In this activity, you will study the environment of the Cretaceous period and look for clues as to what may have caused the extinction. You also will compare current hypotheses about extinction and decide which ones seem most plausible.
Procedure
Part A: Reconstructing the Past
1. Visit the University of California Museum of Paleontology Web Geological Time Machine . Your first task is to see what the environment looked like 70 million years ago [MYA]. Click on "Cretaceous" and learn more about the environment during this time period [146 to 65 MYA] by selecting stratigraphy [rock layers], ancient life, localities [places where fossils have been found], and tectonics [study of the earth's crust]. Pretend you are standing on Earth 70 MYA. Write a page-long journal entry about what you see.
2. Return to the UCMP Web Geological Time Machine and select the Paleocene period, the first period in the Cenezoic Era. Write another journal entry to compare the environment to that of 70 million years ago. How has the habitat changed? What do you think caused the dinosaur extinction? Did it happen suddenly or gradually? Did all dinosaurs become extinct or just individual species? This is what scientists are trying to find out.
Part B: Several Possible Explanations
1. Now you will investigate the different hypotheses that scientists have formulated to solve the mystery of dinosaur extinction. Visit the What Killed the Dinosaurs? Web activity and explore four hypotheses about dinosaur extinction. Record them on the Hypotheses Support form [pdf]. You may want to think of your own hypothesis. Find evidence that supports and refutes each hypothesis and record it on the form.
- Screen grab from the What Killed the Dinosaurs? Web activity.
- What Killed the Dinosaurs? [Flash]
2. Pick the hypothesis you think has the best supporting evidence. Here are some tips:
- Criteria for Choosing the Best Explanation
- A scientific explanation is best if it meets the most criteria:
a. It matches the data from a fair test. [A fair test is an observation or experiment that challenges the validity of a hypothesis. It can support two or more of the alternative possibilities and does not have the same basis as any of the alternative solutions.]
b. It is confirmed by multiple independent fair tests.
c. Initially conflicting data can be shown to agree.
d. The fair test that supports it is particularly strong.
e. There are no conflicting lines of scientific evidence.
f. The alternatives are seriously defective conceptually.
g. The overall weight of evidence is greatly in its favor.
[Adapted with permission from Craig Nelson's page on Fair Tests, Evolution and the Natures of Science Institutes Web site.]
Record your hypothesis and the accompanying evidence on the Best Explanation form [pdf]. You may want to visit some of the resources listed below to gather more evidence.
- DinoBuzz: UCal Berkeley's site on Current Topics Concerning Dinosaurs will introduce you to the debate over the cause of the extinction of the dinosaurs. It discusses the complications that prevent scientists from solving this mystery and provides background on current theories. You might enjoy reading the invalid hypotheses, such as "hay fever killed the dinosaurs."
- Dinosaur Extinction: This very readable site offers background information on dinosaur extinction, the K-T asteroid theory, other K-T extinction theories, and methods used to study extinctions. The section called "studying extinctions," includes a paragraph about radioisotope dating for those interested in one of the current processes used to date fossils.
3. Discuss your choice with a team of fellow classmates. Also discuss the following questions:
- How do scientists use the scientific process to try to figure out why the dinosaurs became extinct?
- Could there be more than one answer?
- Is a new hypothesis called for?
- What do you think it will take to find out?
- Can we ever really know?
Activity 2 Teacher Notes: What Killed the Dinosaurs?
When several explanations are proposed for a phenomenon, how do scientists decide which one is right? In this activity, students learn about the current hypotheses for dinosaur extinction, select the one that seems most reasonable, and gather information to both support and refute it. Students will learn that there is not always a known right answer in science. Sometimes there are questions that have not been answered and may never be answered.
Learning Goals
- To provide a foundation for understanding how scientists use evidence to formulate hypotheses
- To have students understand that there may be more than one hypothesis formed to explain a single phenomenon
- To have students understand that evidence can be used to support more than one hypothesis
- To help students understand that science is not a set of revealed truths [based on faith and the supernatural], but is based on discoveries and evidence found in nature
Procedure:
Part A: Reconstructing the Past
1. Review with your students the definition of a scientific hypothesis.
2. Students will visit the University of California Berkeley Museum of Paleontology site and collect information on the Cretaceous and Paleocene time periods. They will write a page describing this time period from the point of view of someone on Earth at that time. If they need assistance, you might ask: What kinds of plants do you see? What kinds of animals? Describe the arrangement of the continents. What does the environment look like?
Part B: Several Possible Explanations
1. Next, have students visit the What Killed the Dinosaurs? Web activity and read hypotheses for dinosaur extinction. They will take notes on the hypotheses and the evidence that support them. Then they will select the hypothesis they find most reasonable.
- Screen grab from the What Killed the Dinosaurs? Web activity.
- What Killed the Dinosaurs? [Flash]
2. Divide the class into groups of four to five students. Have students discuss the hypotheses they chose and the evidence for and against them. Ask them to print the Hypotheses Support form and Best Explanation form or distribute them yourself.
3. After groups have had enough time to share hypotheses and answer the discussion questions, have a quick follow-up discussion with the entire class. Discuss how scientists form hypotheses, why some hypotheses carry greater weight than others, and whether we will ever be able to solve the mystery of dinosaur extinction. Reinforce the idea that science is a process of establishing cause and effect, not merely finding answers in books or on Web sites. Ask students to think about ways they could "test" their hypotheses.