• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.125-133
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• 2008

The purpose of this study was to compare EMG activities on the lower limb muscles during power walking and mormal walking. Seventeen subjects who have no known musculoskeletal disorders performed walking exercise at a cadence of 140 beats/min. After surface electrodes were attached to rectus femoris, vastus medialis, vastus lateralis, biceps femoris, tibialis anterior, medial gastrocnemius, averageed IEMG and peak IEMG, were measured. The result showed that the power walking did influence the averaged IEMG and peak IEMG. The EMG activity of the quadriceps during power walking was significantly higher than the corresponding values in normal walking during most phases. The averaged IEMG and peak IEMG of gastrocnemius muscles at the end of the double limb stance increased significantly when going from normal walking to power walking. The results indicate that power walking had greater effect on EMG activities on the lower limb muscles and demonstrate that the wide range of benefits can be obtained from power walking in respect to health and fitness. This study suggests that power walking has the potential to improve aerobic fitness and assist in weight management.

• 재활복지
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• v.21 no.3
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• pp.147-163
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• 2017

The purpose of this study was to examine how horse-riding exercise would be effective on the stroke patients' muscle thickness of lower extremity. The 30 stroke patients who were hospitalized in a hospital located in G metropolitan city were selected for this study. These subjects were randomly placed in a horse-riding exercise group (n=15) and a control group (n=15). The horse-riding exercise group received three 20-minute exercises a week for a total of 6 weeks. An ultrasound imaging equipment was used to measured The thicknesses of the rectus femoris (RF), tibialis anterior (TA), medial gastrocnemius (MG), and gluteus medius (GM). After the completion of a 6-week exercise program, same measurement was conducted for all study subjects. The data were analyzed using a paired t-test and independent t-test to determine the statistical significance. As a result, muscle thickness was significantly differentiated before and after the intervention in each group. The thicknesses of all the four muscles significantly increased after exercise in the horse-riding exercise group. The thicknesses of the RF, GM, and TA significantly increased after exercise in the control group. In conclusion, horse-riding exercise increased the thickness of the lower extremity skeletal muscles by stabilizing the knees and activating the extensor muscles of the lower extremities.

• Korean Journal of Applied Biomechanics
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• v.32 no.1
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• pp.17-23
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• 2022

Objective: The aim of this study was to investigate the effect Tiger-step walking on the movement of the lower extremities during walking. Method: Twenty healthy male adults who had no experience of musculoskeletal injuries on lower extremities in the last six months (age: 26.85 ± 3.28 yrs, height: 174.6 ± 3.72 cm, weight: 73.65 ± 7.48 kg) participated in this study. In this study, 7-segments whole-body model (pelvis, both side of thigh, shank and foot) was used and 29 reflective markers and cluster were attached to the body to identify the segments during the gait. A 3-dimensional motion analysis with 8 infrared cameras and 7 channeled EMG was performed to find the effect of tigerstep on uphill walking. To verify the tigerstep effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at α=.05. Results: Firstly, Both Tiger-steps showed a significant increase in stance time and stride length compared with normal walking (p<.05), while both Tiger-steps shown significantly reduced cadence compared to normal walking (p<.05). Secondly, both Tiger-steps revealed significantly increased in hip and ankle joint range of motion compared with normal walking at all planes (p<.05). On the other hand, both Tiger-steps showed significantly increased knee joint range of motion compared with normal walking at the frontal and transverse planes (p<.05). Lastly, Gluteus maximus, biceps femoris, medial gastrocnemius, tibialis anterior of both tiger-step revealed significantly increased muscle activation compared with normal walking in gait cycle and stance phase (p<.05). On the other hand, in swing phase, the muscle activity of the vastus medialis, biceps femoris, tibialis anterior of both tiger-step significantly increased compared with those of normal walking (p <.05). Conclusion: As a result of this study, Tiger step revealed increased in 3d range of motion of lower extremity joints as well as the muscle activities associated with range of motion. These findings were evaluated as an increase in stride length, which is essential for efficient walking. Therefore, the finding of this study prove the effectiveness of the tiger step when walking uphill, and it is thought that it will help develop a more efficient tiger step in the future, which has not been scientifically proven.

• Physical Therapy Korea
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• v.9 no.1
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• pp.17-42
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• 2002

The purpose of this study was to investigate the treatment effect of three interventions on the disuse atrophy of rat hindlimb after two weeks suspension. Forty-eight 11~12 weeks old female Sprague-Dawley white rats were divided into four intervention groups: 1) suspension only (S; n=10), 2) intensive weight bearing treadmill (IWBT; n=10), 3) electrical stimulation (ES; n=9), 4) 2)+3) (ES/IWBT; n=9). Another 10 rats received no intervention or hindlimb suspension and served as controls (C). After the interventions, 1) the cross-sectional area (CSA), 2) the ratio of white muscle fiber composition (WMFC), 3) isometric tetanic tension (ITT), and 4) muscle weights (MWs) were measured from the four calf muscle specimens. The results were as follows: 1. In all intervention groups, the CSAs of medial and lateral gastrocnemius (MG LG), soleus (SOL), and flexor digitorum superficialis (FDS) decreased when compared to the control (C) group (p<.05). The CSA increased in FDS and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group (p<.05). 2. The ratios of WMFC in MG, LG, SOL, and FDS increased compared to the C group for all interventions (p<.05). The ratios of WMFC decreased in SOL and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group, and decreased in SOL for the ES/IWBT group compared to the IWBT group (p<.05). 3. The ITT in the MG, LG, SOL, and FDS decreased compared to the C group for all interventions (p<.05). The ITT increased in MG LG/FDS, SOL, and the whole calf muscles (WCMs) in the IWBT, ES and ES/IWBT groups compared to the S only group (p<.05). 4. The MWs in MG LG/FDS, SOL, WCMs decreased compared to the C group for all interventions (p<.05). The MWs increased in MG LG/FDS and WCMs for the IWBT group, in SOL for the ES group, and in SOL for the ES/IWBT group compared to the S only group (p<.05). 5. In atrophied muscles, the IWBT group showed the best recovery and the ES/IWBT and ES groups followed in decreasing order. The most susceptible muscle to disuse atrophy was the SOL. But conversely, it showed the best recovery in the ES/IWBT group. After two weeks of hindlimb suspension, the calf muscles of rats atrophied and their isometric tension decreased. These changes were best reversed by hindlimb-focused treadmill activity. The next best results were achieved by electrical stimulation combined with the treadmill followed by only electrical stimulation. These findings indicate that full weight bearing treadmill activity alone or in combination with electrical stimulation are effective treatments for non-weight bearing induced muscle atrophy. Further study of the effect of different intensities of electrical stimulation and variations in the duration period of full weight bearing treadmill activity on disuse atrophy is recommended.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.43-48
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• 2012

In this paper, we present the method of gait phases detection using multi biomedical signals during normal gait. Electromyogram(EMG) signals, muscle of thigh angle measurement device and resistive sensors are used for experiments. We implemented a test targeting five adult male and identified the pattern of EMG signal of normal gait. For acquiring the EMG signal, subjects attached surface Ag/AgCl electrodes to quadriceps femoris, biceps femoris, tibialis anterior and gastrocnemius medialis. Resistance sensors are attached to the heel toe and soles of the each feet for measuring attachment state of between feet and ground. Infrared sensors are attached on the thigh and thigh angle measurement device has the range from flection 25 degrees to extension 20 degrees. The results of this paper, The stance and swing phase could be confirmed during the normal gait and be classified in detail the eight steps.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.103-111
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• 2015

Objective : The purpose of this study was to evaluate the effect for running shoes with resilience of midsole on biomechanical properties. Methods : 10 healthy males who had no history of injury in the lower extremity with an average age of 26.5 year(SD=1.84), height of 172.22 cm(SD=4.44) and weight of 67.51 kg(SD=6.17) participated in this study. All subjects ran on the treadmill wearing three different running shoes. Foot pressure data was collected using Pedar-X system(Novel Gmbh, Germany) operating at 100 Hz. Surface EMG signals for biceps femoris, rectus femoris, vastus lateralis, medial lateralis, tibialis anterior, medial gastrocnemius, soleus and peroneus longus were acquired at 1000 Hz using Bignoli 8 System(Delsys Inc., USA). To normalize the difference of the magnitude of muscle contractions, it was expressed as a percentage relative to the maximum voluntary contraction (MVC). The impact resilience of the midsole data was collected using Fastcam SA5 system(Photron Inc., USA). Collected data was analyzed using One-way ANOVA in order to investigate the effects of each running shoes. Results : TPU midsole was significantly wider in contact area than EVA, TPE midsole in midfoot and higher in EMG activity than EVA midsole at biceps femoris. TPE midsole was significantly wider in contact area than EVA midsole in rearfoot and higher in peak pressure than EVA midsole in forefoot. EVA midsole was significantly higher in EMG activity than TPU midsole at tibia anterior. In medial resilience of midsoles, TPE midsole was significantly higher than EVA, TPU midsole. Conclusion : TPU midsole can reduce the load on the midfoot effectively and activate tibialis anterior, biceps femoris to give help to running.

• Advances in materials Research
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• v.3 no.4
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• pp.183-197
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• 2014

Copolymers of gelatin and poly (vinyl alcohol), (PVA) grafted by acrylic acid (AAc) with excellent water absorption and retention abilities under neutral conditions were successfully synthesized using $^{60}Co$ gamma radiations in presence of ammonium persulphate (APS), as water soluble initiator and sodium bicarbonate ($NaHCO_3$) as foaming agent. The optimum synthesis conditions pertaining to maximum swelling percentage were evaluated as a function of gelatin/PVA ratio, amount of water, concentration of APS, $NaHCO_3$, monomer concentration and total irradiation dose. Maximum percent swelling (1694.59%) of the copolymer, gelatin-co-PVA, was obtained at optimum $[APS]=2.92{\times}10^{-1}mol/L$, $[NaHCO_3]=7.94{\times}10^{-2}mol/L$ and 1.5 mL of water at total dose of 31.104 kGy while in case of grafted copolymer, (gelatin-co-PVA)-g-poly(AAc), maximum percent swelling (560.86%) was obtained using $8.014{\times}10^{-1}mol/L$ of AAc in 9 mL water with 31.104 kGy preirradiation dose. The pristine and grafted copolymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron Microscopy (SEM), Thermal gravimetric analysis (TGA) and X-Ray Diffraction (XRD) methods. The copolymers loaded with an antiseptic, Povidone, were used as wound dressing materials for wounded gastrocnemius muscle of mice and the results exhibit that (gelatin-co-PVA)-g-poly (AAc) copolymer is a potent wound dressing material as compared to the copolymer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.153-160
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• 2017

Gait analysis has been conducted in various environments, but the biomechanics during the transition from uphill walking to downhill walking have not been reported. The purpose of this study is to investigate the knee and ankle joint kinematics and kinetics during walking on a triangle-shaped slope compared with those during level walking. Kinematic and kinetic data of eighteen participants were obtained using a force plate and motion capture system. The greater peak ankle dorsiflexion angle and moment and the peak knee extension moment were observed (p<0.05) during both uphill and downhill walking on the triangle-shaped slope. In summary, uphill walking on a triangle-shaped slope, which showed a peak knee flexion of more than $50^{\circ}$ with greater peak knee extension moment, could increase the risk of patellofemoral pain syndrome. Downhill walking on a triangle-shaped slope, which involved greater ankle dorsiflexion excursion and peak ankle dorsiflexion, could cause gastrocnemius muscle strain and Achilles tendon overuse injury.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.487-498
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• 2010

Purpose : To investigate the immediate effects of transcutaneous electrical nerve stimulation(TENS) on the spasticity and the balance in the stroke patients. Methods : 26 subjects with spasticity over lower limbs were allocated randomly into two groups : (1) TENS group, (2) placebo-TENS group. TENS was applied on the both gastrocnemius for 60 minutes(100 Hz, 0.25 ms, 2 times sensory threshold). The modified Ashworth Scale(MAS) and Manual Muscle Tester were used to assess the spasticity of the ankle plantar flexors. Static balance under three conditions was measured by force-plate; in (1) the condition of standing with eyes opened, (2) with eyes closed and (3) the condition of standing on unstable surface with eyes opened. Results : When compared with the pre and post TENS application, TENS showed significant reduction of ankle spasticity in MAS and MMT measurement. Also, Application of high-frequency TENS improved the balance under three conditions. Conclusion : A single session of TENS to stroke patients could reduce spasticity and improve the balance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6767-6773
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• 2014

The study examined the effects of trunk pattern exercise in proprioceptive neuromuscular facilitation (PNF) integrated transcranial direct current stimulation (tDCS) on the muscle activity and balance, walking speed in stroke patient. Thirty-one patients with hemiplegia due to stroke were assigned to either the experimental group (n=15) or control group (n=16). Both groups performed trunk pattern training in PNF for 3 times per week over a 6 week period for 20 minutes per session. The experimental group performed additional tDCS for 20 minutes. A comparison of the two groups after the intervention showed that the exercise program in experimental group had a more significant on the gastrocnemius, tibialis anterior and balance than the control group (p<.05). This showed that trunk pattern exercise in PNF integrated tDCS had a positive effect on the functional recovery of the lower extremity in stroke patients.