What the elliptical asks of the hipEmerging evidence
Your feet stay on pedals that travel in long ovals, so there is no landing: the load under the foot averaged 73% of body weight, against 112% walking and 175% jogging on a treadmill, in 75 adults, and stayed at 70% to 81% across resistance and incline settings in 30. But the hip works differently. In 20 adults on four machines, the trunk, pelvis, hip and knee were all more bent than in walking, with more work from the big buttock muscle (gluteus maximus) and the front of the thigh. In 15 men the hip bent further and the hip flexors had to work harder than in walking, and in 10 adults the front-of-thigh muscle that also bends the hip (rectus femoris) worked harder than in walking, on a treadmill or on a bike.
The side of the hip has it easier. The muscles that hold the pelvis level (the hip abductors) had smaller loads than in walking in 15 men, gluteus medius worked at 6.4% of its maximum on a regular elliptical against 19.1% in a clamshell in 12 adults, and the pelvis dropped less than in treadmill running in 16 runners. Over a session, leg muscle effort was up to 60% lower than running. These are small lab studies in healthy young adults; none measured hip pain.
Sources 4, 5, 6, 7, 8, 9, 10, 11, 12
What nobody has countedEmerging evidence
No study or survey counts hip pain on the elliptical. US emergency departments saw about 70,302 injuries from home exercise machines in 2007 to 2011, about 3,589 of them on ellipticals, and an Australian series of gym injuries didn't report ellipticals separately. The only rating we found: in 18 healthy adults at matched efforts, knee and lower back discomfort didn't differ between an elliptical and an arc trainer, but hip discomfort was higher on the elliptical.
So the map on this page is built from what each condition is known to do. That front-of-hip pain is the commonest, and that the outer hip is relatively spared, is our reading of small lab studies in healthy adults, not a counted fact. Hip pain on the elliptical is most likely with a hip that is already sore, a long or hard session, a high ramp or resistance, a machine whose stride doesn't suit you, or a sudden switch from other training (also our reading).
Sources 1, 2, 3
Foot position, stride, ramp, resistance and directionEmerging evidence
In 16 men, turning the toes out turned the hip out most and gave the lowest glute activity, and a sideways-moving (lateral) elliptical gave the largest hip movements. In 40 young men, hand position, speed and stride length all changed how the lower back moved and which muscles worked. Pedalling backwards moved the hip about 3 degrees further out to the side at the two lowest ramps in 24 adults, and our elliptical guide reports that the ramp changes how far the hip and knee bend.
More resistance raised the load under the foot in 30 adults, and the authors warn of shear forces at the joints, which they didn't measure. No study has measured hip load or hip pain against stride length, pedal width, ramp or resistance, and machines differ: one of four most closely matched walking in the study of 20 adults.
Sources 13, 14, 15, 5, 6
How the causes are told apartEmerging evidence
A consensus says pain from the hip flexors at the front of the groin (iliopsoas-related groin pain) is more likely if resisting hip bending or stretching the front of the hip hurts, and in a review of mostly low-quality studies, treatment without surgery worked for most people with it. A deep pinch at the top of the stride in a younger active adult can be hip impingement, which a consensus says needs symptoms, examination signs and imaging together; a painless snap is usually a tendon and harmless, while deep groin pain with catching suggests the labrum.
From mid-life, a stiff groin ache with short morning stiffness is often arthritis, which the National Institute for Health and Care Excellence (NICE) diagnoses without imaging. Hip joint pain was felt in the buttock in 71% of 51 people and in the thigh and groin, and none in the lower back, while NHS inform says problems felt in the hip can come from the back. Outer hip pain from the gluteal tendons is worse lying on that side and sitting with the legs crossed, and a review links it with compression of the tendons and the thigh drifting inwards.
Sources 16, 17, 18, 19, 20, 21, 22, 23, 27
Groin lumps, stress fractures and children's hipsStrong evidence
A hernia lump may get bigger when you cough or strain and smaller when you lie down. Most femoral hernias (a small lump at the top of the thigh) become strangulated, and strangulation is a medical emergency, while a painless inguinal hernia may not need treatment, the NHS says. A stress fracture of the hip (femoral neck) causes gradual groin pain, worse with activity and weight bearing and easing with rest, mostly in distance runners, and needs imaging the same day.
Hip pain in a child should always be checked, the NHS says: it is usually irritable hip, but it can be a joint infection, a fracture or Perthes' disease, which is commonest from 4 to 9. A slipped upper femoral epiphysis (SUFE), from about 11, can feel like a pulled muscle in the hip, knee or thigh.
Sources 24, 25, 26, 28, 29, 30, 31
When a scan helps, and how it usually goesEmerging evidence
Not at first for most: NICE diagnoses hip arthritis from symptoms, and impingement needs the clinical picture first, with imaging to confirm it; labral tears are also common on scans of hips that don't hurt. A suspected stress fracture needs an X-ray and, if that is normal, an MRI (magnetic resonance imaging) scan the same day.
The NHS says see a GP if hip pain hasn't improved after 2 weeks at home. Outer hip pain is slow: NHS inform says it can take 6 to 12 months of rehabilitation to settle, though in the LEAP trial 51 of 65 people rated themselves a success at a year with education and exercise, against 31 of 60 with wait and see. For hip-related pain in active adults, exercise-based care should last at least 3 months. In children, irritable hip usually gets better in 1 or 2 weeks. No one can promise a date.
Sources 20, 18, 28, 32, 22, 33, 34, 29
