The Acute Effects of Hip and Knee Exercises on Pain Sensitivity in Young Adult Females With Long-standing Patellofemoral Pain - a Randomized Crossover Study.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Change in Pain pressure threshold (PPT) at the center of patella.
Study Overview
Brief Summary
Patellofemoral pain (PFP) is highly prevalent in both adolescent and adult populations and as much as 91% of those affected experience ongoing knee pain for up to 20 years after the initial diagnosis.
Exercise-based treatment focusing on strengthening the muscles around the hip and knee is usually effective when treating patient with PFP. However, this approach has proven ineffective in a subgroup of females who have suffered from PFP for multiple years.
This group was found to have a significantly lower tolerance for pressure stimuli compared to healthy controls. This indicating that central mechanisms within the nervous system rather than the problem being the knee itself.
Exercising a non-painful muscle distant to a painful part of the body has previously been effective in deceasing pain in affected area. This mechanism has been investigated in patients with long-standing musculoskeletal pain as well as healthy populations.
Related research has suggested that a possible link between patients perception of painful stimuli an the pain-reducing effect of exercise exists. As such, patients witch experienced a pain reducing effect of exercise was found to be able to tolerate more pain than before the intervention.
The aim of this study is to assess if exercising a distant non-painful muscle around the hip has a larger acute pain-reducing effect on knee pain compared to knee specific exercises in female patients with long-standing PFP.
Detailed Description
Background: Patellofemoral pain (PFP) has a high prevalence in both adolescent and adult populations (7% and 15%) and as much as 91% of those affected experience ongoing knee pain for up to 20 years after the initial diagnosis. Exercise-based treatment focusing on strengthening the muscles around the hip and knee is usually effective when treating patient with PFP. However, this approach has proven ineffective in a subgroup of females with long-standing PFP. This group was found to have altered condition pain modulation indicating facilitated central mechanisms. A localized analgesic effect by exercising a distant non-painful muscle has been observed previously in patients with long-standing musculoskeletal pain. This is known as exercise induced hypoalgesia. In relation, an increased condition pain modulation was found to be a predictor for an increase in the effect of exercise induced hypoalgesia, indicating a link between the two mechanisms. The aim of this study is to assess if exercising a distant non-painful muscle around the hip has a larger acute analgesic effect on localized knee pain compared to knee specific exercises in female patients with long-standing PFP.
Study design: This study is a randomized, controlled, participant and assessor blinded crossover study. The study will be conducted at the Research Unit of General Practice in Aalborg. Reporting of the study will follow the CONSORT guidelines for randomized trials of Non-pharmacologic Treatment.
Method: Thirty women between the age of 20 and 25 with current knee pain which they have experienced ongoing or recurrent for a duration of 5 years will be randomized to either a knee or hip specific resistance exercise as their first intervention. After a washout period of 15 minutes, the participant will perform the other exercise. The participants will undergo a test-procedure before the first exercise, between the exercises and after the final exercise. The test-procedure consist of handheld pressure algometry and cuff pressure algometry assessing pain pressure threshold, pain detection threshold and pain tolerance threshold. Condition pain modulation and temporal summation of pain will be assessed by cuff algometry. In order to assess knee pain in relation to the exercises, the participants will be asked to rate their knee pain before and after each exercise set. The primary outcome will be pain pressure threshold assessed by handheld pressure algometry at the center of patella of the test limb.
Recruitment: A random sample of participants from the APA2011 cohort who experience ongoing PFP in 2016 will be invited to participate in this study. The participants will be contacted by telephone and invited to participate in the study. Verbal information regarding the study will be provided over the phone and written material will be send by e-mail. In case the cohort provide an insufficient number of participants, patients from general practice will be sought out and invited to participate. This process will be done in collaboration with general practice clinics in the area. If the combination of the above-mentioned strategies does not provides the required number of participants, online social-medias like Facebook and Twitter will be used as a mean to obtain a sufficient number of participants.
Allocation sequence: The participants will be randomized to do either sitting knee extension or sidelying hip abduction first. A computer generated allocation sequence will be conducted at www.random.org by an independent researcher. This individual will put slips of paper, which says either "Hip" or "Knee" into opaque sealed envelopes. The envelopes will be marked with sequential numbers. When the first participant have underwent the baseline testing he or she will be assigned the ID number 1 (ID1). After completing the baseline test this participant will proceed to the exercise room where the exercise instructor will be waiting. The exercise instructor will then select the envelope marked "ID1" and note if the participant was assigned to the hip or knee exercise as the first exercise.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Double (Participant, Outcomes Assessor)
Masking Description
The outcome assessor will be blinded to the order of the exercises and the participants will be blinded to the study-hypothesis.
Eligibility Criteria
- Ages
- 20 Years to 25 Years (Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Participants with PFP are required to have current non-traumatic anterior or retropatellar knee pain which they have experienced ongoing or recurrently for a duration of at least 5 years.
- •At least two of the following daily activities should provoke knee-related symptoms: prolonged sitting or kneeling, squatting, running, hopping, or stair walking, tenderness on palpation of the patella or double leg squatting.
- •Worst pain during the previous week have to be of more than 3 cm on a 10-cm visual analog scale (VAS).
Exclusion Criteria
- •Patients who have sustained a traumatic injury to the hip, knee, ankle or the lumbar spine within the past 3 month will be excluded.
- •Other identifiable knee conditions in isolation (that is, not occuring concurrently with PFP. As an example, if the subject has isolated patellar tendinopathy they will be excluded. If the subject has PFP and concurrent pain at the patellar tendon, they will be included).
- •Individuals with rheumatoid arthritis, knee joint effusion, self-reported patellofemoral instability, known malign conditions, neurological disease or previously knee surgery will be excluded as well.
- •In cases with suspicion of serious pathology a rheumatologist will be consulted.
Outcomes
Primary Outcomes
Change in Pain pressure threshold (PPT) at the center of patella.
Time Frame: This will be assessed at 1) baseline, 2) approximately 5 minutes after the first exercise intervention (hip or knee) and 3) approximately 5 minutes after the second exercise intervention (hip or knee).
The acute effect of hip versus knee exercises on PPT at the center of patella will be compared. These measures will be taken from the test limb. PPT is defined as the point where pressure becomes painful and will be assessed by handheld pressure algometry (SOMEDIC Electronics, Solna, Sweden). The pressure will be applied with at a rate of 30 kPa/s at a perpendicular angle, to a 1cm2 area on the skin surface. Subjects will be given a handheld switch and will be instructed to press it as soon as the stimulus changes from pressure to pain. PPT will be measured twice at each time-point and the average will be calculated and used for the analyses. A mark will be drawn on the center of patella to make sure the two measures are taken from the same site. There will be a 30-second break between each measurements.
Secondary Outcomes
- Change in PPT at the muscle belly of the m. tibialis anterior.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in PPT at the lateral epicondyle on the contralateral elbow.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in pain detection threshold (PDT) measured with cuff pressure allometry at the lower leg of both limbs.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in pain tolerance threshold (PTT) measured with cuff pressure allometry at the lower leg of both limbs.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in temporal summation of pain assessed by cuff pressure allometry at the lower leg of the test limb.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in condition pain modulation assessed by cuff pressure allometry at the lower leg of the test limb.(This will be assessed at 1) baseline, 2) within 20 minutes after completing the first exercise intervention (hip or knee) and 3) within 20 minutes after completing the second exercise intervention (hip or knee).)
- Change in self-reported pain before and after each exercise set reported on a numeric pain rating scale (NPRS).(This will be assessed during the first exercise intevention (hip or knee) and approximately 30 minutes after, during the second exercise intervention (hip or knee).)
Investigators
Michael Skovdal Rathleff
Associate Professor
Aalborg University