Effects of Bicycle Saddle Height on Knee Injury Risk and Cycling Performance

Abstract

Incorrect bicycle configuration may predispose athletes to injury and reduce their cycling performance. There is disagreement within scientific and coaching communities regarding optimal configuration of bicycles for athletes. This review summarizes literature on methods for determining bicycle saddle height and the effects of bicycle saddle height on measures of cycling performance and lower limb injury risk. Peer-reviewed journals, books, theses and conference proceedings published since 1960 were searched using MEDLINE, Scopus, ISI Web of Knowledge, EBSCO and Google Scholar databases, resulting in 62 references being reviewed. Keywords searched included 'body positioning', 'saddle', 'posture, 'cycling' and 'injury'. The review revealed that methods for determining optimal saddle height are varied and not well established, and have been based on relationships between saddle height and lower limb length (Hamley and Thomas, trochanteric length, length from ischial tuberosity to floor, LeMond, heel methods) or a reference range of knee joint flexion. There is limited information on the effects of saddle height on lower limb injury risk (lower limb kinematics, knee joint forces and moments and muscle mechanics), but more information on the effects of saddle height on cycling performance (performance time, energy expenditure/oxygen uptake, power output, pedal force application). Increasing saddle height can cause increased shortening of the vastii muscle group, but no change in hamstring length. Length and velocity of contraction in the soleus seems to be more affected by saddle height than that in the gastrocnemius. The majority of evidence suggested that a 5% change in saddle height affected knee joint kinematics by 35% and moments by 16%. Patellofemoral compressive force seems to be inversely related to saddle height but the effects on tibiofemoral forces are uncertain. Changes of less than 4% in trochanteric length do not seem to affect injury risk or performance. The main limitations from the reported studies are that different methods have been employed for determining saddle height, small sample sizes have been used, cyclists with low levels of expertise have mostly been evaluated and different outcome variables have been measured. Given that the occurrence of overuse knee joint pain is 50% in cyclists, future studies may focus on how saddle height can be optimized to improve cycling performance and reduce knee joint forces to reduce lower limb injury risk. On the basis of the conflicting evidence on the effects of saddle height changes on performance and lower limb injury risk in cycling, we suggest the saddle height may be set using the knee flexion angle method (25-30°) to reduce the risk of knee injuries and to minimize oxygen uptake.

Effects of Saddle Height on Performance and Muscular Activity During the Wingate Test

“…Due to specific adaptations in muscle properties we expected better anaerobic performance at the reference position, which was not confirmed. We suggest that saddle height should be chosen by taking into consideration other factors such as comfort 30 and pedaling technique 19 . However, these aspects were not evaluated in the present study.…”

Effects of Increased Saddle Height on Length and Activity Pattern of Vastus Lateralis and Biceps Femor is Muscle

“…Hamley & Thomas(1967)는 인심(inseam: 바닥부터 낭심까지의 길이) 길이의 109%의 안장 높이가 최적 페달링을 위한 안장 높 이라고 제안한 바 있으며 (Pruitt & Matheny, 2006), Holmes, Pruitt, & Whalen(1991) 안장 높이(saddle height)의 변화는 하지의 운동학적 변화를 통해 근육의 길이(muscle length)와 수축 속도(contraction velocity)에 변화를 가져올 수 있다 (So et al, 2005;Sanderson & Amoroso, 2009). 이와 관련해 페달링 파워와 최적의 안장 높이 의 선정 방법에 관한 연구가 최근까지 다양하게 시도되었으나 (Pruitt & Matheny, 2006;Bini, Hume, & Croft, 2011;Peverler & Green, 2011), 안장 높이와 부하, 분속수에 따라 다양한 논쟁이 이루어지고 있다. 또한, 근육은 해부학적 부착형태에 따라 단관 절 근육(mono-articular muscle)과 다관절 근육 (multi-articular muscle)으로 나눌 수 있으며, 이는 고관절, 무릎관절, 발목관절 의 상대적인 신전과 굴곡정도에 따라 그 역할이 달라질 수 있 다 (So et al, 2005).…”

“…Sanderson, Martin, Honeyman, & Keefer(2006) 의 연구에서 분속수(cadence) 변화를 통한 페달링 시 발목관절 의 신전에 관여하는 대표적인 두관절 근육(bi-articular muscle)인 비복근(gastrocnemius muscle)과 단관절 근육(mono-articular muscle)인 가자미근(soleus muscle)의 근육 활성화 패턴 차이를 살펴본 바 있으며, Jacobs, Bobbert, & van Ingen Schenau(1993) (Cannon, Kokhorst, & Cipriani, 2007). 대표적인 단관절 근육인 대퇴의 외측광근(vastus lateralis muscle)은 파워 구간(power phase or propulsion phase)에서 크랭크 회전 시 추진력에 필요한 기계적 에너지의 34~39%의 기여를 하는 것으로 보고된 바 있 으며 (Raasch, Zajac, Ma, & Levine, 1997) (Bini et al, 2011;Holmes et al, 1994;Peveler & Green, 2011). (Hawkins & Hull, 1990;Sanderson et al, 2006).…”

“…(Hawkins & Hull, 1990;Sanderson et al, 2006). 산출된 각도데이터로부터 관절의 최대 신전시점(Peak extension timing)과 가동범위(ROM_joint)를 구하였으며, Hawkins & Hull(1990) (Bini et al, 2011). 이러 한 방법은 안장 높이의 변화가 각 피험자의 익숙한 안장 높이 를 벗어남에도 불구하고, 무릎관절에 무리를 주지 않고 (Holmes et al, 1991) 꾸준히 훈련할 경우에 긍정적인 효과를 나타낼 수 있는 안장 높이 (Peveler & Green, 2011) (Connick & Li, 2012).…”

“…이에 반 해 두 관절 근육인 대퇴이두근은 고관절 신전과 동시에 무릎 굴곡근으로 작용하며, 페달링 시 파워구간에서 주동근에 대항 하여 하지를 적절히 조율하는 길항근의 기능을 담당한다 (So et al, 2005;Raasch et al, 1997). 이러한 단/다관절 근육의 활성화 특징은 하퇴 및 대퇴 근육에서 유사한 결과를 나타내었다 (Connick & Li, 2012 (Heil, Derrick, & Whittlesey, 1997;Bini et al, 2011;Seo et al, 2012) …”