The specific symptoms you’ll experience with a pulled hip flexor muscle depends upon the severity of the strain. Given the location of the strain and the six muscles involved, it is often difficult to pinpoint the actual muscle(s) affected.
Common symptoms of a strained hip flexor muscle include:
- sudden, sharp pain in the upper hip, lower back, front of thigh, and groin where it meets the pelvis during exercise – most usually felt during sprinting, kicking, or high knee movements.
- pain upon standing or sitting
- swelling and tenderness
- bruising in the hip flexor, hip, thigh, or groin (indicates blood vessels have been broken)
- overall weakness in the hip flexor muscles
Due to the location of the pain, hip flexor strains are often confused with groin strains. One way to determine which you have is that groin pulls will usually cause pain when you perform lateral movements (e.g., cutting sideways) while hip flexor strains do not. Additionally, again due to location, injury to the upper quadriceps can mimic symptoms of a hip flexor strain.
There are numerous possible causes of a pulled hip flexor muscle, however, let’s take a look at some of the most common causes:
- strong contraction of the hip flexor muscles
- high kicks or knee movement (e.g., soccer, improper martial arts movements)
- lack of flexibility in the hip flexor muscles
- repeated movements that strain flexor muscles over time (e.g., cycling, particularly with improperly adjusted seat height)
- poor hip flexor strength
- being overtired or not warming up prior to stressful activity
- overstretching the hip flexor (pushing the muscles past their tension threshold)
- sudden stress upon hip flexor muscles
- impact to the hip flexor muscles by an outside force
Additionally, you are at risk for a hip flexor strain if you are exercising with while tired, during cold weather, or if you’ve had a previous hip flexor muscle injury.