Stretching can affect balance ability by generating biomechanical and physiological changes in the postural muscles. Stretching of the lower extremity muscles can greatly affect posture maintenance strategies and balance ability. However, the relationship between stretching and balance ability has not been clarified. Therefore, this study aimed to investigate the effect of plantar flexor stretching on balance ability. Forty-four healthy young adults were randomly assigned to four groups (static stretching, dynamic stretching, ballistic stretching, and control). Ankle joint range of motion, static balance ability, and dynamic balance ability were evaluated before, immediately after, and 20 min after stretching. Stretching did not affect balance ability in the open-eye condition. After stretching, the sway area was significantly reduced in the closed-eye condition (p < 0.05). After stretching, the reach distance of dynamic balance ability increased significantly (p < 0.05). The results show that plantar flexor stretching can positively affect balance ability. Therefore, plantar flexor stretching should be considered a rehabilitation method to improve balance.

Background and Objectives: Weight-bearing activities exacerbate pain and fatigue in functional flat foot, with uphill walking presenting additional challenges due to increased external loads. The current study investigates whether 3D-printed customized arch-support insoles can enhance gait variables and ankle alignment during uphill walking. Materials and Methods: Twenty healthy young adults, divided into two groups (normal foot condition (control, n = 10), functional flat foot (FF, n = 10)), walked on a treadmill at a 10% incline under two conditions: wearing shoes alone (shoe) or wearing shoes with 3D-printed customized arch-support insoles (SI). Gait pattern, center of force (COF), and ankle joint angles were analyzed by OptoGait, Tekscan, and Kinovea, respectively. Results: The foot flat phase of the gait pattern was prolonged in individuals with FF compared to the control under both shoe and SI conditions, whereas the propulsive phase was shortened with the SI. Medial deviation of the COF during the propulsive phase, observed in individuals with FF under the shoe condition, was corrected to a more lateral alignment with the SI, resembling the COF alignment of the control. Additionally, individuals with FF under the shoe condition exhibited increased ankle pronation compared to the control, whereas the SI moderated pronation, achieving alignment closer to that of the control. Conclusions: These findings indicate that the 3D-printed customized arch-support insoles can improve gait mechanics and ankle alignment in individuals with FF, particularly under challenging conditions such as uphill walking.

Background/Objectives: Functional flat foot (FF) is associated with altered lower limb biomechanics, leading to inefficient load transfer and potential overuse injuries. Customized orthoses, such as 3D-printed insoles and toe spreaders, may mitigate these deficits, but their combined biomechanical and neuromuscular effects remain unclear. The current study investigated the immediate effects of 3D-printed arch support insoles (SI) and toe spreaders (Toe) and their combination (SI+Toe) on gait pattern, center of force (COF), ankle alignment, and lower limb muscle activation in young adults with FF. Methods: Ten FF individuals and ten matched controls performed level walking under four randomized conditions: shoe-only, SI, Toe, and SI+Toe. Gait was analyzed using OptoGait, COF trajectory via F-Scan, ankle angles using Kinovea, and muscle activity (semitendinosus, biceps femoris, tibialis anterior, peroneus longus, gastrocnemius, and soleus) via surface EMG. Results: Compared to controls, FF individuals exhibited medial COF deviation, increased ankle eversion, and altered muscle activity. In the FF group, SI+Toe reduced medial COF deviation, decreased eversion, and prolonged foot flat while shortening the propulsive phase. Semitendinosus and tibialis anterior activity increased under SI+Toe, while gastrocnemius and soleus remained reduced during propulsion. Conclusions: The combined utilization of 3D-printed insoles and toe spreaders produced immediate measurable improvements in foot alignment and muscle activity patterns in FF individuals. These findings support that integrating customized orthotic designs with toe spreader elements may provide a practical, non-invasive approach for improving lower limb biomechanics. Such strategies may help improve foot mechanics and reduce compensatory muscle activation in a clinical setting.

Background and Objectives: Scapular muscles are crucial in controlling scapular movement, ensuring proper alignment, and preventing injuries during shoulder joint motion. The shoulder abduction angle is one of the most important factors when performing exercises to improve scapular movement control. The Pilates reformer arm work (AW) movement can be performed with different shoulder abduction angles. Therefore, this study analyzed the differences in scapular muscle activation depending on the shoulder abduction angle during the AW movement. Materials and Methods: Twenty-six healthy adult males performed the AW movement under four shoulder abduction angle conditions (0°, 90°, 135°, 160°). When performing the AW in the four conditions, surface electromyography analyzed the muscle activation of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), serratus anterior (SA), posterior deltoid (PD), and levator scapulae (LS), and the muscle activation ratios of the UT/LT, LS/LT, UT/SA, and LS/SA. Results: The UT, LT, and SA muscle activation increased proportionally with the increasing shoulder abduction angle (p < 0.001). The LT showed the highest muscle activity at the shoulder abduction angle of 135° (p < 0.001). The MT and PD showed the highest muscle activities at the shoulder abduction angle of 90° (p < 0.001). The muscle activity ratios of the UT/LT and LS/LT were the lowest at the shoulder abduction angles of 90° and 135° (p < 0.001). The muscle activity ratio between the UT/SA and LS/SA was the lowest at the 135° and 160° shoulder abduction angles (p < 0.001). Conclusions: Our findings highlight the impact of the shoulder abduction angle on scapular muscle activation, suggesting that different angles may be used to engage specific muscles during Pilates reformer arm work exercises selectively. This insight can guide exercise interventions for individuals aiming to improve their scapular control and stability.

Among the Pilates-based exercises, the modified side-arm (MSA) and modified high-five (MHF) are commonly used for shoulder strengthening and rehabilitation. This study examined shoulder girdle muscle activity and ratios across different spring intensities. Twenty-two healthy males performed the MSA and MHF using yellow (low), blue (medium), and red (high) springs. Surface electromyography (EMG) was used to measure serratus anterior (SA), lower trapezius (LT), levator scapulae (LS), upper trapezius (UT), and middle deltoid (MD) muscle activity, along with LS/SA, LS/LT, and UT/LT ratios during concentric, isometric, and eccentric phases. Muscle activities were generally higher in the MHF than in the MSA with the same spring. Both exercises demonstrated a proportional increase in activity with spring intensity, though the activity of the SA and LT in the MHF plateaued. MHF ratios were significantly higher with the red spring. These findings indicate that the MHF stimulates shoulder girdle muscles more than the MSA, and that the MSA can further stimulate shoulder girdle muscles by increasing spring intensity. Additionally, optimal spring intensity exists in the MHF for targeting shoulder stabilization muscles. However, excessive spring intensity during the MHF may lead to abnormal compensation, emphasizing the need for careful spring intensity progression.

Background and Objectives: Stroke patients often experience changes in their pelvic tilt, trunk impairments and decreased gait and balance. While various therapeutic interventions have been attempted to improve these symptoms, there is a need for interventions that are easy to apply and reduce the physical labor of physical and occupational therapists. We aimed to investigate the immediate effects of two different methods of trunk elastic taping on the pelvic inclination, trunk impairment, balance, and gait in chronic stroke patients. Materials and Methods: We performed a single-blind randomized controlled trial involving 45 patients with chronic stroke. Participants were randomly assigned to one of three groups: forward rotation with posterior pelvic tilt taping (FRPPT, n = 14), backward rotation with posterior pelvic tilt taping (BRPPT, n = 14), or placebo taping (PT = 14). This study was conducted from December 2023 to January 2024. All the measurements were performed twice: before the intervention and immediately after the intervention. The pelvic inclination was assessed using the anterior pelvic tilt angle. The trunk impairment scale (TIS) was used to measure the trunk impairment. The balance and gait were evaluated using a force plate and walkway system. Results: The pelvic inclination was significantly different in the FRPPT and BRPPT groups compared to the PT group (p < 0.05, p < 0.001). The TIS and gait were significantly increased in the FRPPT group compared to the PT group (p < 0.05). The balance significantly improved in the FRPPT and BRPPT within groups (p < 0.05). Conclusions: Two different methods of posterior pelvic tilt taping improved the anterior pelvic tilt in chronic hemiplegic stroke patients compared with PT, and the FRPPT method also improved the trunk impairment and gait. Therefore, posterior pelvic tilt taping can be used as an intervention with immediate effect.