Patellofemoral pain syndrome (PFPS) is a musculoskeletal disorder that often occurs in the lower extremities of athletes and has a high prevalence in women aged 18–35 years. It also had an appropriate VMO : VL ratio similar to sling-based hip adduction exercise and had beneficial effects on PFPS.
The sling-based closed kinetic knee extension exercise produced the highest VMO activation. VMO activations during the sling-based open and closed kinetic knee extension exercises were significantly higher ( P = 0.04 and P = 0.001) than those during hip adduction exercises and VMO : VL ratio for the sling-based closed kinetic knee extension and hip adduction exercises approximated to 1. Thirty male (age = 21.19 ± 0.68 y) and 30 female (age = 21.12 ± 0.74 y) patients with PFPS were recruited. The VMO and VL activations and VMO : VL ratios for the three exercises were analyzed and compared. Sling-based open and closed kinetic knee extension and hip adduction exercises were designed for PFPS, and electromyography was applied to record maximal voluntary contraction during the exercises. To examine what changes are caused in the activity of the vastus medialis oblique (VMO) and vastus lateralis (VL) at the time of sling-based exercises in patients with patellofemoral pain syndrome (PFPS) and compare the muscular activations in patients with PFPS among the sling-based exercises. You would usually place these fins as far back of your board as possible for maximum down the line trim.Objectives.
Sometimes you can find them with a straighter, more vertical forward edge with a curved side aft, and sometimes they’re found with curved edge forward and vertical edge aft. With a super wide base combined with a super wide tip, these fins get their name from generally appearing in the shape of a D. A little harder to turn and not as stable when you’re on the nose, this fin is more for getting maximum trim straight down the line. Usually you see these on a more classic, heavier log. The D Fin (with no flex) isn’t going to be the most forgiving fin or the most versatile to surf.
You can also still step on the tail and pivot (swing) the board around in a relatively tight radius. It’s designed to slow you down a little and help keeps the tail further in the water while you’re up on the nose. You can recognize this fin by it’s full, vertical outline with a wide base. The Pivot Fin (with very little flex) is your standard go-to fin-shape for nose riding. This combines nicely the projection and maneuverability of the flex fin with some of the hold you get from a Pivot Fin. With a wide base like before but with a little more width in the tip of the fin you can see a fairly vertical base that sweeps back towards the end. The Rake Fin (with medium flex) is the next most flexible and sits between the flex fin and the pivot fin along the spectrum. This reflects what we mentioned earlier where the more rake you have in your fin, the more you can draw out your turns compared with a rigid upright fin template for more pivot in tighter turns. When coming off a bottom turn, your flex fin will give you a ton of projection. These flex fins are going to feature a wider base that tapers down into a narrow tip and doesn’t offer too much drag. The Flex Fin (with maximum flex) is a really versatile fin that can be used in just about anything from shorter stubbies to 10-foot nose riders. Now let’s move to a longboard and check out how it’s going to perform using four different fin shapes: the Flex Fin, the Rake Fin, the Pivot Fin, and the D Fin.įlex your fins! The degree of flex from least flex to most from left to right: The Flex Fin, the Rake Fin, the Pivot Fin and the D Fin. More details on flex will follow, but for the purpose of this article, lets look at how flex and shape of fins go hand in hand. It contributes to your projection out of turns, which in turn will produce your speed and affect control. When you get down to it, thrusters, quads, side fins are more or less variations of these characteristics just in a smaller version.įlex is one of these characteristics that can directly relate to fin performance. One way to comprehend this is to use a Single Fin for our descriptions. Your fin’s shape impacts directly on how your surfboard is going to perform. Now that you’ve got the basics and all the lingo for fins, you need to understand a little more complicated aspects about how fin shape can contribute to the overall surfing performance.
0 kommentar(er)
