The thigh adductor squeeze test: 45° of hip flexion as the optimal test position for eliciting adductor muscle activity and maximum pressure values

Abstract

The thigh adductor squeeze test is commonly used in the diagnosis of groin injuries. Currently no reports exist in the published literature which, detail the level of activation of the adductor musculature during the test as well as concomitant pressure values. Thus the aim of the present study was to investigate adductor muscle activity and concomitant pressure values during the performance of the thigh adductor squeeze test at 0°, 45°, and 90° of hip flexion. Eighteen Gaelic games athletes without any history of groin injury participated. Each participant performed 3 repetitions of the thigh adductor squeeze test in the three positions of 0°, 45°, and 90° of hip flexion. Adductor musculature surface electromyographic activity (bilateral) and pressure values quantified using a commercially available sphygmomanometer were recorded for each test. The greatest pressure values were observed in the 45° of hip flexion test position (0°: 202.50 ± 57.28 mmHg; 45°: 236.76 ± 47.29 mmHg; 90°: 186.11 ± 44.01 mmHg; P < 0.05). Similarly, the greatest amount of adductor muscle activity was observed in the 45° of hip flexion test position (P < 0.05). The combined results of the present study suggest that the 45° of hip flexion test position is the optimal thigh adductor squeeze test position for eliciting adductor muscle activity and maximum pressure values.

Introduction

Groin injuries are common complaints in team sports such as soccer (Waldén et al., 2005), rugby (O’Connor, 2004), and Australian rules football (Orchard and Seward, 2002), where running, change of direction, and kicking tasks are required. A comprehensive Australian rules football epidemiological study by Orchard and Seward (2002), reported that an average of almost twelve games per club was missed each season between 1997 and 2000 due to groin injuries. Coupled with this, groin injuries accounted for 3.3% of all injuries, equating to an incidence of 3.9 injuries per 1000 playing hours. While much research has been conducted on groin injuries in sports such as Australian rules football and soccer (Verrall et al., 2005, Malliaras et al., 2009), there have been relatively few studies focussing on groin pathology in Gaelic games athletes. Gaelic games are the traditional indigenous sports played in Ireland. There are two individual codes, Gaelic football and hurling. Both codes are high velocity sports with physiological demands such as agility, speed and strength similar to Australian rules football, rugby union and rugby league. A recent prospective study investigating the incidence of injuries in Gaelic football identified that groin injuries account for 9% of all injuries sustained (Wilson et al., 2007).

One of the primary roles of clinicians involved in the treatment and rehabilitation of sports injuries and particularly for clinicians involved directly with athletic squads is injury prevention and screening. The thigh adductor squeeze test has been identified as a useful diagnostic tool in identifying groin pain (Verrall et al., 2007), while it has also been shown to be accurate and reliable in the measurement of adductor muscle strength (Malliaras et al., 2009, Fulcher et al., 2009). The test consists of placing a measurement device (e.g. dynamometer or sphygmomanometer) between an individual’s knees and asking them to forcibly adduct both legs in order to compress the device (Malliaras et al., 2009, Fulcher et al., 2009). A recent study by Crow et al. (2010) indicated that hip adductor muscle strength is decreased both preceding and during the onset of groin injury in elite under-age Australian footballers. Furthermore, Engebretsen et al. (2010) have also shown that weak adductor muscles are an intrinsic risk factor for the development and onset of groin injuries. Thus the role of injury screening on a regular basis cannot be over-estimated.

Currently no reports exist in the published literature, which detail the level of activation of the adductor musculature during the test positions of the thigh adductor squeeze test (i.e. 0°, 45°, and 90° of hip flexion) which are commonly utilised in a clinical setting. Previous research in our laboratory has established the reliability of the thigh adductor squeeze test performed in the positions of 0°, 45°, and 90° of hip flexion; with the 45° of hip flexion test position demonstrating the lowest standard error of measurement, standard error of measurement percent and minimal detectable change (Delahunt et al., in press). As the adductor musculature is frequently injured in field-based athletes (Orchard and Seward, 2002, O’Connor, 2004, Waldén et al., 2005), there is a need to determine the level of muscle activity present during the thigh adductor squeeze test in order to assist injury screening and prophylactic evaluation of athletes. Furthermore an electromyographic (EMG) analysis of adductor muscle activity during the performance of the thigh adductor squeeze test could provide important information relating to the amount of force being applied to the anterior and medial pelvic rings via the adductor musculature attachments; thus giving an indication of the optimal test position to be utilised during injury screening.

Thus the aims of the present study were to investigate the level of adductor muscle surface EMG (sEMG) activity and concomitant pressure values in a healthy population of male Gaelic games athletes during performance of the thigh adductor squeeze test in the three commonly utilised test positions.