Time Difference Between Onsets of Lateral And Medial Hamstring Muscles During Gait in Patients With Patellofemoral Pain.

Bahçeşehir University

Status: Completed

Conditions: Patellofemoral Pain

Treatments: Other: Q angle measurement; Other: kujala patellofemoral pain scale; Diagnostic Test: Surface EMG

Study type: Interventional

Funder types: Other

Identifiers

NCT03392688

BahcesehirU

Details and patient eligibility

About

Early activation of lateral hamstrings (LH) in respect of medial hamstrings (MH) may cause abnormal knee abduction and external rotation moments in individuals. This situation may increase the risk of ligament injury and may be the reason for susceptibility of patellofemoral pain (PFP). The aim of this study is to compare the time delays in electromyographic studies between medial and lateral hamstrings in patients with PFP and asymptomatic subjects.

Full description

Patellofemoral pain (PFP) is a very common complaint in younger population with still unclear and controversial etiology. It was suggested that a combination of intrinsic and extrinsic factors cause PFP. The strain of the retropatellar subcondral bone caused by excessive lateral patellar tracking is known to be the one among intrinsic factors (Thomee R.1999). Imbalance of the dynamics between knee extensor muscles, Vastus Medialis (VM) and Vastus Lateralis (VL), has also received a great research interest during last 10 years. However, uneven timing between onsets of counterpart knee flexor muscles, Lateral and Medial hamstring, were just considered as a possible etiological factor of the PFP (Patil S.2011), yet this hypothesis remains to be proven. The investigators aimed to investigate whether there is a relative time delays of the LH (biceps femoris, BF) and MH (semitendinosus, ST) during the walking at the self-selected speed in patients with patellofemoral pain. Even though dynamic EMG investigations are challenging because of cross-talks between muscles, hence difficult to determine clearly onset times, the investigators think that any information acquired during walking would be highly important because patellofemoral pain is mainly exaggerated by dynamic activities.

15 patients who were diagnosed with PFP (age 28.73±7.44, height 169.73±7.09, weight 67.47±14.31) and 15 asymptomatic subjects (age 30.47±6.22, height 167.87±7.81, weight 67.87±13.48) were recruited in the study. The inclusion criteria for PFP subjects was presence of the anterior and retropatellar pain for minimum 2 months scaled as 3 in accordance with Numeric Analog Scale during at least two of the following activities: stair descending, ascending, squatting, prolonged sitting, jumping, sitting on the knees. Surface EMG was recorded from Medial Hamstring and Lateral Hamstring muscles at 1000 Hz sampling rate during walking at participants' normal walking speed. EMG data obtained from 5 gait trials were evaluated. The EMG traces were full wave rectified and low pass filtered at 50 Hz. Delay in timing before heel strikes between MH and LH was calculated. Statistical significance between differences in time delays was analysed using "paired sample t-test".

Enrollment: 30 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criterias:

• Pain originating specifically from the patellofemoral articulation (vague or localized);
• At least 3/10 pain intensity accordingly to the Numeric Analog Scale (NAS) with at least 2 of the following functional activities commonly associated with PFP stair ascent or descent, squatting, kneeling, or prolonged sitting;
• Reports of pain greater than 2 months in duration.
• Being between 18-40 years of age

Exclusion Criterias:

• Previous history of knee surgery,
• History of patellar instability,
• Neurologic involvement that would influence gait

Trial design

Primary purpose: Screening

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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30 participants in 2 patient groups

Patellofemoral pain group

Experimental group

Description:

Diagnosis of PFP was established based on symptoms, physical examination performed by an orthopedic surgeon. Patients were also screened through physical examination to rule out ligamentous or meniscal injuries, patellar tendinitis and knee joint effusion by an orthopedic surgeon. All patients also underwent a radiologic examination consisting of AP, lateral and tangential radiograms. Surface EMG, Kujala patellofemoral pain scale, Q angle measurement were administered to the PFP group.

Treatment:

Other: Q angle measurement

Diagnostic Test: Surface EMG

Other: kujala patellofemoral pain scale

Control Group

Active Comparator group

Description:

Control group had similar demographic characteristics with PFP group, and neither one of the controls had any knee pathology or current knee pain or effusion that would effect the gait. Surface EMG, Q angle measurement were administered to the control group.

Treatment:

Other: Q angle measurement

Diagnostic Test: Surface EMG