Constant Resistance During Proportional Speed Provoked Higher Lower Limb Proximal Musculature Recruitment than Distal Musculature in Young Healthy Adults

The lack of exercise in society today often leads to severe muscle loss and poor physical performance. Training methods targeting specific weakened muscle groups can help prevent or counteract muscle loss. This study aimed to analyze how the lower extremity muscles are activated when pushing a sled with constant resistance at two different speeds. Twenty-six participants with an average age of 23.77 years consented to having electromyography surface electrodes placed along the gluteus maximus (GMax), gluteus medius (GMed), tibialis anterior (TA), and gastrocnemius (GA) of their dominant leg. Muscle activation levels were then measured while the participant walked and ran with and without sled resistance. The study results showed that muscle activation was comparable during all trials and was not influenced by speed or constant resistance. However, the muscle activation for GMax and GMed was significantly higher than the activation levels exhibited by GA and TA. While pushing a sled has been shown to impact all studied musculature similarly, adding resistance to the movement can affect gait parameters such as stride length and cadence. Our findings support the use of sled training in patients with hip pathologies who are seeking to strengthen their GMax and GMed

Constant Resistant at Different Speeds while Pushing a Sled Prompts Different Adaptations in Neuromuscular Timing on Back and Lower Limb Muscles

Resistance training (RT) is commonly used to target specific weakened muscle groups. Among the plethora of methods employed as RT, the current study focused on a sled that provides constant resistance proportional to speed. This study aimed to examine neuromuscular patterns of the lower extremity and trunk muscles in response to pushing a sled with constant resistance at two different speeds. Twenty-six young adults (average age, 23.8) participated in this study. Surface electromyography electrodes were placed on gluteus maximus (GMAX), gluteus medius (GMED), tibialis anterior (TA), gastrocnemius (GA), and erector spinae (lumbar and thoracic) of their dominant leg or side (unilateral at the same side as the dominant lower limb). Neuromuscular timing was collected during four tasks: walking, running, walking-pushing the sled (WP), and running-pushing the sled (RP). All gait activities were repeated twice, with self-selected speed and an equivalent distance of 40 feet. A MANOVA analysis showed that during WP, GMED and GMAX showed more neuromuscular recruitment than leg and trunk muscles when compared to walking. During RP, the thoracic musculature was significantly more involved than any other muscle during running. Based on our findings, we recommend that physiotherapists and trainers use this sled with constant resistance during walking in patients with pelvic or hip weakness. Further, we suggested utilizing the sled in subjects requiring mid-trunk activation at faster speeds, such as fast walking or running

Delivering Sustained, Coordinated, and Integrated Observations of the Southern Ocean for Global Impact

The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time series of key variables, and deliver the greatest impact from data to all key end-users. Although the Southern Ocean remains one of the least-observed ocean regions, enhanced international coordination and advances in autonomous platforms have resulted in progress towards addressing the need for sustained observations of this region. Since 2009, the Southern Ocean community has deployed over 5700 observational platforms south of 40°S. Large-scale, multi-year or sustained, multidisciplinary efforts have been supported and are now delivering observations of essential variables at space and time scales that enable assessment of changes being observed in Southern Ocean systems. The improved observational coverage, however, is predominantly for the open ocean, encompasses the summer, consists of primarily physical oceanographic variables and covers surface to 2000 m. Significant gaps remain in observations of the ice-impacted ocean, the sea ice, depths more than 2000 m, the air-sea-ice interface, biogeochemical and biological variables, and for seasons other than summer. Addressing these data gaps in a sustained way requires parallel advances in coordination networks, cyberinfrastructure and data management tools, observational platform and sensor technology, platform interrogation and data-transmission technologies, modeling frameworks, and internationally agreed sampling requirements of key variables. This paper presents a community statement on the major scientific and observational progress of the last decade, and importantly, an assessment of key priorities for the coming decade, towards achieving the SOOS vision and delivering essential data to all end users

A Clinical Teaching of Hamstring Strains

CLINICAL PRESENTATION & EXAM: A patient with a hamstring strain will have pain and tenderness on his or her posterior thigh. The patient may also complain of difficulty extending the knee and sitting comfortably. Depending on the severity of the injury, there could be bruising and swelling in the thigh area causing a loss of hamstring strength. If one of the hamstring muscles is completely torn; the patient would feel a “popping” sensation upon injury. Thus, the patient would be unable to use the injured leg. A hamstring strain typically comes from muscle overload during an eccentric contraction. A muscle overload can occur when the hamstring muscles are stretched during a sprint or loaded while the muscles help the back leg push off from the ground. The specific type and severity of the injury can be diagnosed upon palpation of maximally painful and swollen areas. ANATOMY & PATHOLOGY: When a hamstring muscle is strained there is a partial or complete tear of the muscle. The tear typically occurs in the muscle belly but also can occur where the muscle fibers join the tendon. There are three hamstring muscles: semitendinosus, semimembranosus, and biceps femoris. The hamstring muscles are located on the posterior thigh extending from the ischial tuberosity to the top of the tibial tuberosity or fibula in the lower leg. The main function of the hamstrings is to decelerate the movement of the lower leg in the sagittal plane when running or kicking. The hamstring muscles also are responsible for knee flexion, hip extension, stabilizing the knee, and internal and external rotation of the lower extremity. Any activity such as climbing or running actively involves the hamstring muscles. DIAGNOSTIC TESTING & CONSIDERATIONS: A hamstring strain can be diagnosed through a physical examination. The physician pinpoints the exact location of the muscle and/or tendon that has been damaged through palpation. Practitioners can assess the severity of the hamstring strain based on the range of motion and muscle strength of the injured leg compared to the healthy leg. MRIs and ultrasound imaging can be used to view the muscle or tendon tears. In rare cases, an avulsion fracture can occur when a small piece of bone is detached from the main bone when the hamstring tears. X-ray images are used to detect if an avulsion fracture is present. TREATMENT & RETURN TO ACTIVITY: After a hamstring injury occurs, the patient should immediately halt any athletic or strenuous activities. Equipment such as crutches or a cane may be used to keep weight off the injury. Wrapping the injury to provide compression, icing the injured area, and elevating the affected leg helps reduce inflammation. Most hamstring strains are nonoperative. However, if the hamstring muscle is completely torn away from its connecting bone, then surgery will be necessary to reattach the muscle. Once the swelling subsides, the patient can work with a physical therapist to strengthen the hamstring muscles and increase flexibility/mobility. Therapists focus on eccentric strength training, neuromuscular control of the lumbopelvic region, and therapeutic massage. Biking and walking are some simple exercises that will help strengthen the hamstring muscles before fully returning to activity. Most hamstring tears take at least a few weeks to recover and some can take months depending on the location and cross-sectional area of the muscle tear