By David C. Holzman
Early afternoon found us downshifting into low as the grade abruptly steepened. Soon we were rising high above the coastal plains, towards Stevens Pass, elev. 4061 feet.
Yet the unexpected ease of pedaling my 30-pound, 1972 Peugeot bicycle, with 20 pounds of gear in the panniers up the Cascades made that day, July 16, 1975 (the beginning of a cross-country trek from Seattle to Boston) unusually memorable. Long after the trip was over, I would dream of cycling up mountains, with the same euphoric feeling as when dreaming of flight.
What a contrast to the previous summer’s trip, a 500-mile loop from Watertown to Burlington, VT, and back. On Day One I’d knocked off, exhausted, at midday, after struggling 50 miles over six hours, gaining a mere thousand feet of altitude.
At the end of that 10-day haul, I rode back to the Bicycle Repair Collective on Broadway in Cambridge (now the Broadway Bicycle School), where I’d learned bicycle mechanics, to check out the bike. It’s normal for a bicycle chain to stretch with use. Twelve chain links should measure 12 inches, but an extra eighth of an inch is no big deal. Mine was stretched half an inch.
I was perturbed. I’d bought and installed the chain just before the trip, and I was sure the it must have been defective to have stretched so far. But the mechanic on duty was having none of it. He claimed I’d pedaled too slowly. What???!
How could this mechanic have any idea how fast I’d been pedaling? He hadn’t been riding with me! That, he said, was simple: had I been riding with proper cadence, I wouldn’t have stretched the chain half an inch in a mere 500 miles.
Besides stretching the chain, the slow pedaling apparently was putting my knee joints at greater risk for several maladies: patellar chondro-malacia (or what some doctors call patellofemoral syndrome), which can range from minor inflammation to damage to the cartilage on the underside of the kneecap; patellar tendonitis; bursitis; and even arthritis. Another potential knee injury is ileo-tibial band syndrome. In that case, the pain is on the outside of the knee.
Pedaling slowly and pushing hard increases the sheer stress you put on the bearing surfaces of your knee joint, where the cartilage of your kneecap slides along the cartilage of your femur as the joint flexes. (The femur and tibia also articulate, but for cyclists, the weak point in the joint is generally the cartilage of the kneecap.)
But Vijay Jotwani, MD, of Houston Methodist Orthopedics and Sports Medicine, says that such injuries are unlikely unless there’s a muscle imbalance or biomechanical abnormality. “A muscle imbalance refers to the variation in strength or coordination of one muscle group that opposes another,” says Jotwani. “For example, for patellofemoral syndrome, the outside part of the quadricep muscle (vastus lateralis) may be stronger than the inside part (vastus medialis), which then pulls the kneecap to the outside when the entire quadriceps contracts.”
Biomechanical abnormalities are more likely to be problems for women, says Jotwani. Their wider hips can result in a slight outward angle at the knee in an unbent leg. Pedaling pressure can then pull the kneecap slightly out of its groove. Jotwani says that various leg weight-lifting exercises can mitigate these problems.
An improperly fitting bicycle, and a too-low seat can also raise the risk of knee injury, says Greg Cloutier, MPH, Project Manager for the Human Performance and Exercise Science Lab at Northeastern University.
Frequently I see cyclists grimacing as they bear down upon the pedals, and I wonder if they think the bulkier, stronger muscles they build this way will make them faster cyclists. If so, they are wrong. While a modicum of muscle is necessary, the thing that enables one to climb steadily, or pedal all day, is power. Continue reading