National Football League

FAN GUIDE: A look at common football injuries

Published Sep. 17, 2015 4:00 a.m. ET

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NEW YORK (AP) Sprains and strains. ACLs, MCLs and patellar tendons.

In one painful instant, they can derail your favorite football team's championship hopes - or sink your dreams for a title-winning fantasy football squad.

NFL teams are required to provide injury reports during the regular season after each of the three final full practices leading up to games. They can be downright lengthy, reading like a laundry list of maladies from jammed fingers to sprained ankles to concussions.

Concussions, or traumatic head and/or brain injuries, in particular have received a lot of attention in recent years as teams and players constantly try to reduce the risk for potentially career-ending injuries, while looking to improve treatments.

What about the other injuries fans constantly hear about? Here's a look at some common football-related injuries you'll hear throughout the season, designed to help you know how all of your teams - college, NFL and fantasy - might be affected:

ACHILLES TENDON RUPTURES

The Achilles is the longest and strongest tendon in the body, and stretches from the heel to the calf, a springy band located behind the ankle just above the heel that helps players push off their feet, jump and accelerate.

Due to overuse or excessive force placed on the tendon, it can tear or rupture. Surgery is typically necessary to bring the ends back together, sidelining a player for several months due to extensive rehab needed.

In the past, repairing the injury required a large incision, but advances in medical technology have spawned some minimally invasive procedures that make only 1- to 2-inch incisions, said Dr. Thom Mayer, the NFL Players Association medical director.

Most players return after 9 months, although Baltimore linebacker Terrell Suggs played within 6 months of his surgery.

ACL/PCL/MCL/LCL TEARS

The anterior cruciate, medial collateral, posterior cruciate and lateral collateral ligaments are all located in the knee and serve different purposes. The ACL connects the thigh bone to the shin bone in the front of the knee, and is one of the most common injuries among NFL players. While a sprain could sideline a player for a few weeks, a tear can end a season. Among those who tore their ACLs in training camp this summer included Green Bay wide receiver Jordy Nelson, Dallas cornerback Orlando Scandrick and Carolina wide receiver Kelvin Benjamin.

''There's very few exceptions to the ACL being anything other than a season-ending injury if it's a tear,'' Mayer said.

The PCL is located behind the ACL, criss-crossing it to form an ''X'' in the center of the knee.

The MCL connects the thigh bone to the shin bone on the inner side of the knee, while the LCL connects the thigh bone to the top of the lower leg, or fibula, and is located on the outer side of the knee. MCL injuries are most common among offensive lineman and often require several weeks to recover.

HAMSTRING INJURIES

The hamstring is actually a group of four muscles that run along the back of the thigh, stretching from the hip to the knee and help a person bend their leg at the knee. These injuries vary in severity, and in turn, their timetable in sidelining a player.

A mild pull of one of the muscles, commonly referred to as a Grade I injury, can sideline a player for a few days to a couple of weeks and can be a lingering, nagging condition if not sufficiently rested and healed. A Grade II hamstring injury involves a partial tear, while a Grade III injury is a complete tear of the hamstring that could require surgery and is likely season-ending.

HIGH ANKLE SPRAIN

These can stop players in their tracks. In a high ankle sprain, the ligaments above the ankle - which connect the tibia to the fibula - are affected rather than the ligaments outside the ankle in a low ankle sprain. High ankle sprains make up only about 15 percent of all ankle sprains in the general population, according to Mayer, but comprise closer to 20-25 percent of ankle sprains in the NFL due to the high-energy rotational forces involved. They're far more serious and take much longer to recover from - six to eight weeks, and sometimes longer - than a classic ankle sprain, which might sideline a player for several days to two weeks.

HIP POINTER

It doesn't sound particularly menacing, but could sideline a player for a week or a couple of months, depending on the severity. It is basically bruising in the pelvis and abdomen area, usually caused by blunt force - such as a hard tackle. The bleeding can affect several other muscles in the area, making it difficult for a person to run or even walk.

''Part of the blood is hemoglobin, and hemoglobin includes iron and the iron portion of that when it's in the connective tissue or the bone is very irritating,'' Mayer said. ''To a certain extent, that's where the pain comes from.''

LISFRANC INJURIES

A serious foot injury that can be career-threatening because of its complexity. A Lisfranc sprain or fracture is an injury in the middle of the foot in which at least one (or sometimes, all) of the small bones (or metatarsals) is broken or the ligaments that support the foot in that area are torn. New York Jets wide receiver Santonio Holmes needed a metal plate and two screws inserted into his foot after his joints separated in the middle of his foot in 2012 and was sidelined for nearly a year. Even a minor sprain not requiring surgical repair could take six to eight weeks to heal.

MENISCUS TEARS

The meniscus is a crescent-shaped rubbery disc of cartilage - ''a shock absorber,'' Mayer says - on the inside and outer edges of the knee. Both of those help a person balance weight across the knee. When a meniscus is torn - commonly by a sharp turn or twist - the knee can lock up and swell. A minor tear can be treated with rest, but a severe tear could require surgery that may sideline an athlete for several weeks or even months. In the past, these injuries could be career-ending, but arthroscopic procedures today can get players back on the field.

OBLIQUE STRAINS

An oblique strain involves the muscles on the side of the body between the ribs and pelvis. This type of injury can occur when a player takes a hard hit to the waist area, or from overuse or sudden use of the muscles - for instance, a quarterback throwing a pass or a defensive back defending a receiver. Oblique strains are usually treated with rest and could take a few weeks to heal, or could become a lingering issue otherwise. They're also common in baseball.

PATELLAR TENDON INJURIES

The patellar tendon allows a person to straighten a leg by acting with the quadriceps. Technically, it's a ligament because it connects the kneecap to the shin bone. Giants wide receiver Victor Cruz missed the last 10 games of last season after tearing his patellar tendon. Complete tears or ruptures often need to be surgically sewn back together, and recovery is at least four to six months.

PLANTAR FASCIITIS

An injury that affects the bottom of the foot and can lead to intense heel pain. Plantar fasciitis occurs when the ligament supporting the arch of the foot - the plantar fascia - is strained, and worsens when small tears develop in the ligament. The injury can sap players of speed while they deal with it. Rest, icing of the arch and finding new footwear are among the typical treatments. It can linger for months.

TURF TOE

Some fans who are unfamiliar with this injury might downplay the severity because of its non-threatening name. But make no mistake: Turf toe can sideline players for six to eight weeks and is extremely painful. It occurs when the ligaments under the joint of the big toe are sprained or ruptured as a result of the toe being hyperextended. It makes it extremely difficult to push off and cut.

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