Limb symmetry during double-leg squats and single-leg squats on land and in water in adults with long-standing unilateral anterior knee pain; a cross sectional study

Abstract

BackgroundThe presence of pain during movement typically results in changes in technique. However, the physical properties of water, such as flotation, means that water-based exercise may not only reduce compensatory movement patterns but also allow pain sufferers to complete exercises that they are unable to perform on land. The purpose of this study was to assess bilateral kinematics during double-leg squats and single-leg squats on land and in water in individuals with unilateral anterior knee pain. A secondary aim was to quantify bilateral asymmetry in both environments in affected and unaffected individuals using a symmetry index.MethodsTwenty individuals with unilateral knee pain and twenty healthy, matched controls performed body weight double- and single-leg squats in both environments while inertial sensors (100 Hz) recorded trunk and lower body kinematics. Repeated-measures statistics tested for environmental effects on movement depths and peak angles within the anterior knee pain group. Differences in their inter-limb symmetry in each environments was compared to the control group using analysis of variance tests.ResultsWater immersion allowed for greater movement depths during both exercises (double-leg squat: +7 cm, p = 0.032, single-leg squat: +9 cm, p = 0.002) for the knee pain group. The double-leg squat was symmetrical on land but water immersion revealed asymmetries in the lower body frontal plane movements. The single-leg squat revealed decreased hip flexion and frontal plane shank motions on the affected limb in both environments. Water immersion also affected the degree of lower limb asymmetry in both groups, with differences also showing between groups.ConclusionsIndividuals with anterior knee pain achieved increased squat depth during both exercises whilst in water. Kinematic differences between the affected and unaffected limbs were often increased in water. Individuals with unilateral anterior knee pain appear to utilise different kinematics in the affected and unaffected limb in both environments.

The Use of Wearable Sensors in Human Movement Analysis in Non-Swimming Aquatic Activities: A Systematic Review

“…Moreover, the authors provided information about the three kinds of usage that each sensor has: (i) accelerometer (range: ±2 g, ±6 g; bandwidth: 50 Hz; resolution: 14 bit; noise: 128 ug/ . Two other studies used five sensors (tri-axial accelerometer and gyroscope) with an acquisition frequency of 100 Hz [15,16]. None of the four selected studies report any kind of information about the sensors' sealing.…”

“…The study by Fantozzi et al [12] reported that the participants were healthy (males and females), and Severin et al [16] reported such data per sex. Other studies split the participants into healthy or with some pathology (in that study, particular cases had chronic anterior knee pain) and did not mention the participants' sex [15]. It only mentioned that both groups (young adults with chronic anterior knee pain and healthy adults) were age and sex matched.…”

“…Three studies used eight sensors and allocated them in the thorax (one sensor), pelvis (one sensor), thighs (two sensors), shanks (two sensors), and feet (two sensors) [12][13][14]. The remaining studies [15,16] used five sensors and allocated them in the thorax (one over the spinous process of the third thoracic vertebra), in the thighs (two attached bilaterally to the participant's lateral mid-thigh), and in the shanks (two attached bilaterally to the participant's lateral shank). Table 2.…”

“…The two remaining studies [15,16] analyzed the difference (in the inclination angles of the trunk, thighs, and shanks) between specific movements that can be performed in water: squat, split squat, and single-leg squat. In one study, the authors quantified the differences between movements [16], and in the other study the authors assessed the asymmetries between healthy participants and participants with chronic anterior knee pain [15]. Table 2 presents in detail all variables analyzed in each study, and Table 3 the summary of the main results of each study.…”

“…However, the use of sensors in such water-based activities in comparison to swimming is rather scarce [12,13]. Basically, such studies aimed to compare the walking pattern on dry land and in underwater conditions [12], propose movement analysis methodology based on inertial and magnetic sensors [14], assess the kinematics of underwater walking [13], perform some specific movements/exercises (e.g., squat and some variants) [15,16], compare abdominal pressure between dry land and underwater conditions [17], or monitor handicap people in hydrotherapy sessions [18]. The body of knowledge about the use and application of sensors technology is widely explored in a swimming perspective, with original studies and some systematic reviews.…”