• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.12 no.1
• /
• pp.16-26
• /
• 2006

The purpose of this study was to investigate the influence of the various knee angles and ground state on the muscular activities and fatigue of the ankle muscles by integrated electromyograms (iEMG) and median frequency of tibialis anterior (TA), peroneus longus (PL), flexor digitorum longus (FDL) and gastrocnemius (GC). Ten healthy male subjects were participated into stable and balance ball sessions at four angles of knee joint. The surface electromyograms (sEMG) were recorded from the TA, PL, FDL and GC on stable and balance ball with full weight bearing at four knee angles of $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$. The time serial data of the surface electromyographic signals were transformed into integrated and frequency serial data by fast fourier transformation. On the stable ground, the iEMG signals of the TA, PL, FDL and GC were significantly higher at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). On the balance ball, the iEMG of the TA, PL, FDL and GC were significantly higher at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). The median frequency of the TA, PL, FDL and GC were significantly lower at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee on the stable ground (p<0.05). On the balance ball, also the median frequency of the TA, PL, FDL and GC were significantly lower at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). The iEMG of the TA, PL, FDL and GC were significantly higher on the balance ball at $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee angles compared with stable ground. The median frequency of the TA, PL, FDL and GC were significantly lower on the balance ball at $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee angles compared with stable ground. These results indicate that the ground conditions and angles of the knee joint involved to muscular activities and fatigue of ankles muscles, may performed at first on stable ground and then balance ball in order to $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee flexion.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.197-206
• /
• 2005

The purpose of this study was to quantify the maximum EMG levels and determine if there are differences in these EMG levels with respect to different knee flexion angles. Eight university students with no known musculoskeletal disorders were recruited as the participants. The maximum voluntary isometric knee extensions and flexions were taken from each participant sat on the isokinetic exercise machine (Cybex 340) at five different knee flexion angles ($10^{\circ}$, $30^{\circ}$, $50^{\circ}$, $70^{\circ}$, $90^{\circ}$) After surface electrodes were attached to rectus femoris, vastus medialis, vastus laterlis, biceps femoris, and semitendinosus, maximum EMG levels at five different knee flexion angles were measured. The results showed that there was no significant difference in maximum EMG levels among five different knee flexion angles. Although there was no significant difference in EMG levels and were some variations among different knee flexion angles, the EMG signals of quadriceps in extension and biceps femoris in flexion were the greatest at $30^{\circ}$. It seems that different joint angles or relative locations of body segments might affect the magnitude of EMG levels. Because the maximum EMG levels could change with a different knee flexion angle, an attempt should be made to more accurately measure these values. If then, %MVIC measure provides more reliable data and is most appropriate for EMG normalization.

• The Journal of Korean Physical Therapy
• /
• v.32 no.1
• /
• pp.52-57
• /
• 2020

Purpose: This study compared the muscle activities of the Vastus medialis oblique (VMO) and the Vastus lateralis (VL) at three different knee extension angles: 90°, 135°, and 180° in the sitting position. Methods: Twenty subjects between 20 and 30 years of age participated in the study. A mobile phone application called the Clinometer was used to measure the knee joint angle. Electromyography (EMG) was performed to measure the muscle activities of the VMO and VL muscles during knee isometric extension exercises. The pulling sensor was used to maintain 70% of the maximum strength of the knee extensor continuously in the sitting position. After attaching the EMG sensor, the subjects were asked to perform isometric knee extension exercises randomly among three knee extension angles (90°, 135°, or 180°) in the sitting position. One-way repeated measures analysis of the variance and a Bonferroni post hoc test was used to identify the VMO and VL muscle activity during knee extension angles among 90°, 135°, and 180°. Results: The VMO and VL muscle activities increased with increasing knee extension angle in the sitting position (p<0.01). Conclusions: Knee extension exercise at a 180° angle in the sitting position can be recommended to increase the muscle activity of the VMO and VL muscle activities efficiently.

• PNF and Movement
• /
• v.10 no.3
• /
• pp.25-31
• /
• 2012

Purpose : This study was intended to compare muscle activity in relation to knee joint angles on closed kinetic chain. Methods : A total of 13 subjects consisting of 5 adult males and 8 adult females were made to make movements maintaining knee joint angles at $30^{\circ}$, $45^{\circ}$ and $90^{\circ}$ on closed kinetic chain and the muscle activity occurring in their vastus medialis, rectus femoris and vastus lateralis was measured. Statistical data were analyzed using oneway ANOVA. Results : On closed kinetic chain, the muscle activity of the vastus medialis, rectus femoris and vastus lateralis increased the most at $90^{\circ}$ among the knee joint angles with statistically significant differences(p<0.05). Conclusion : On closed kinetic chain, it could be seen that as the angle of the knee joint increased, the muscle activity increased.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.11 no.1
• /
• pp.39-44
• /
• 2013

Purpose : The purpose of present study is to evaluate the joint angles of legs in the standing posture for six patients with unilateral knee osteoarthritis. Methods : The participants underwent unilateral total knee replacement. A motion analysis was used to measure the joint angles of the hip, knee, and ankle. The measurements were taken before the surgery, one week and two weeks after the surgery. Both sides of the legs were evaluated. Results : This result showed that after a certain healing period, both hip joint angles showed a significant difference while there was no significant difference in the knee and ankle joint angles. After surgery, the angle of ankle dorsiflexion was smaller on the operated side than the opposite side compared to the pre-surgery measurements. Conclusion : After surgery, the asymmetry in a standing position left unchanged due to contracture of the knee joint and tightness in the hamstring muscle. Therefore, when physiotherapists plan an initial exercise programs for TKR patients, it is essential to apply adequate exercises which consider the contracture of the leg joints.

• The Journal of Korean Physical Therapy
• /
• v.16 no.2
• /
• pp.108-115
• /
• 2004

The aim of this study is to present the basic reference data of age and specipic gait parameters for comparisons of the gait characteristics depended on Unilateral Trans-Femoral or Trans-Tibial Prostheses. The basic gait parameters were extracted from 10 Adult, 10 above knee(A/K) patients and 10 below knee(B/K) patients, 50 to 60 years of age using VICON 512 Motion Analyzer. The results were as follows; 1) The mean Cadence of the above knee(A/K) patients and below knee(B/K) patients were $87.77{\pm}8.64$ steps/min, to $99.84{\pm}11.14$ steps/min.(p<0.05) 2) The mean Walking Speed of the above knee(A/K) patients and below knee(B/K) patients were $0.84{\pm}0.15$ m/s, to $0.96{\pm}0.25$ m/s.(p>0.05) 3) The mean Stride Length of the above knee(A/K) patients and below knee(B/K) patients were $1.14{\pm}0.14$ m, to $1.14{\pm}0.22$m.(p>0.05) 4) The mean maximal angles of joint on the hip flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $34.75{\pm}10.18_{\circ}$, to $32.32{\pm}6.34_{\circ}$ .(p>0.05) 5) The mean maximal angles of joint on the knee flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $66.97{\pm}15.08_{\circ}$, to $52.65{\pm}9.21_{\circ}$ .(p<0.05) 6) The mean maximal angles of joint on the ankle dorsiflexion motion for different above knee(A/K) patients and below knee(B/K) patients were $14.41{\pm}4.82_{\circ}$, to $10.04{\pm}3.49_{\circ}$ .(p>0.05) 7) The mean maximal angles of joint on the ankle plantarflexion motion for different above knee(A/K) patients and below knee(B/K) patients were $5.77{\pm}3.17_{\circ}$, to $2.75{\pm}4.49_{\circ}$ .(p>0.05)

• The Journal of Korean Physical Therapy
• /
• v.15 no.3
• /
• pp.166-172
• /
• 2003

The aim of this study is to present the basic reference data of age and specific gait parameters for comparisons of the gait characteristics depended on amputation length of the Unilateral Trans-Tibial Prostheses. The basic gait parameters were extracted from 10 Adult, and 20 below knee(B/K) patients, 50 to 60 years of age using VICON 512 Motion Analyzer. The results were as follows; 1. The mean Cadence of the above knee(A/K) patients and below knee(B/K) patients were $87.77{\pm}8.64$ steps/min, to $99.84{\pm}11.14$ steps/min.(p<0.05) 2. The mean Walking Speed of the above knee(A/K) patients and below knee(B/K) patients were $0.84{\pm}0.15$ m/s, to $0.96{\pm}0.25$ m/s.(p>0.05) 3. The mean Stride Length of the above knee(A/K) patients and below knee(B/K) patients were $1.14{\pm}0.14\;m$, to $1.14{\pm}0.22m$.(p>0.05) 4. The mean maximal angles of joint on the hip flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $34.75{\pm}10.18_{\circ}$, to $32.32{\pm}6.34_{\circ}$.(p>0.05) 5. The mean maximal angles of joint on the knee flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $66.97{\pm}15.08_{\circ}$, to $52.65{\pm}9.21_{\circ}$. (p<0.05) 6. The mean maximal angles of joint on the ankle dorsi-flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $14.41{\pm}4.82_{\circ}$, to $10.04{\pm}3.49_{\circ}$.(p>0.05) 7. The mean maximal angles of joint on the ankle plantar-flexion motion for different above knee(A/K) patients and below knee(B/K) patients were $5.77{\pm}3.17_{\circ}$, to $2.75{\pm}4.49_{\circ}$.(p>0.05)

• Korean Journal of Applied Biomechanics
• /
• v.25 no.3
• /
• pp.293-300
• /
• 2015

Objective : The purpose of this study was to compare the kinematic data of the horizontal rotation movements of shoulder, hip, knee during two-handed backhand drive stroke according to two different ball directions. Methods : The kinematic variables were analyzed such as the joint angles of the lower body, horizontal rotation angles of the shoulder, hip, inter-knee segment, body twist angle and difference in angle of forward swing. Two-handed backhand drive stroke was analyzed through a three-dimensional motion analysis. The collected data were analyzed by a paired t-test, and the statistical significant value was set at ${\alpha}=.05$. Results : The findings of this study were as follows; First, there was no difference in the total angles of lower limb joints from the forward swing position to impact posterior. Second, there was no difference in the horizontal rotation angles of E1 shoulder, hip, and E2 shoulder but the horizontal rotation angles of E1 knee, E2 hip, knee, E3, and E4 shoulder, hip, and knee were different in all events. Third, there was no difference in the body twist angle of the maximum horizontal rotation. In addition, there was no difference in the angle of the body twist by the ball direction in the shoulder-hip, the hip-knee and the shoulder-knee. Conclusion : Horizontal rotation angle determines ball directions.

• Physical Therapy Korea
• /
• v.14 no.3
• /
• pp.57-63
• /
• 2007

The purpose of this study was to evaluate inter-rater reliability of the amplitude and first knee extension angles in deep tendon reflex test by using an electrical hammer. Twenty-five healthy adults participated in the study. Compound muscle action potential is elicited by tapping the knee tendon with an electrical hammer in deep tendon reflex tests. The amplitude and knee extension angle were simultaneously measured. The mean value of the amplitude and the knee extension angles through three time trials for each tester, are used for determining the inter-rater and Intra-class Correlation Coefficients (ICCs) reliabilities. According to the results, the ICCs of the amplitude is .280 and that of the knee extension angle is .789. Pearson correlation coefficients of the amplitude of the action potential and the knee extension angles are .685, showing significant statistically moderate correlation. Inter-rater reliability in the amplitude was not significant. More objective and quantitative deep tendon reflex tests should be done to obtain higher reliability in further studies.

• Physical Therapy Korea
• /
• v.20 no.4
• /
• pp.1-8
• /
• 2013

This study analyzes how different knee flexion angles affect the abdominal and pelvic muscle activity during supine bridging. Twenty healthy subjects participated in the study. We used surface electromyography (EMG) to measure how three different knee flexion angles ($100^{\circ}$, $70^{\circ}$, and $40^{\circ}$) affected the activity of the transverse abdominis/internal oblique (TrA/IO), external oblique (EO), biceps femoris (BF), rectus femoris (RF), and gluteus maximus (GM) muscles on the dominant side during supine bridging. The one-way repeated analysis of variance (ANOVA) was used to determine the statistical significance of TrA/IO, EO, BF, RF and GM muscle activity and the GM/BF activity ratio. For the TrA/IO, EO, BF, and GM muscles, supine bridging with different knee flexion angles resulted in significant differences in abdominal and pelvic muscle activity. For the TrA/IO muscles, the post-hoc test demonstrated that muscle activity significantly increased at $40^{\circ}$ compared to $70^{\circ}$; however, there were no significant differences between $100^{\circ}$ and $70^{\circ}$ or $100^{\circ}$ and $40^{\circ}$. For the EO muscle, the post-hoc test demonstrated that muscle activity significantly increased at $40^{\circ}$ compared to $100^{\circ}$ and $70^{\circ}$; no significant difference was observed between angles $100^{\circ}$ and $70^{\circ}$. For the BF muscle, the post-hoc test demonstrated that muscle activity significantly increased according to the knee flexion angle ($40^{\circ}$ > $70^{\circ}$ > $100^{\circ}$). For the GM muscle, the post-hoc test demonstrated that muscle activity significantly increased according to the knee flexion angle ($100^{\circ}$ > $70^{\circ}$ > $40^{\circ}$). However, for the RF muscle, there was no significant difference. Additionally, the GM/BF activity ratio significantly increased according to the knee flexion angle ($100^{\circ}$ > $70^{\circ}$ > $40^{\circ}$). From these results, we can conclude that bridging with a knee flexion of $100^{\circ}$ can strengthen the GM muscle, whereas bridging with a knee flexion of $40^{\circ}$ is recommended to strengthen the IO, EO, and BF muscles. We can also conclude that knee flexion angles should be modified during supine bridging to increase the muscle activity of different target muscles.